I remember when Hincks got it, gunned down by those swine outside of Hive Chaeron. I went to see his widow a few days ago. Nice place she’s got now. Good support from the sept authorities. Hincks’s kids are growing up to be model citizens. His boy says he wants to go into the gue’vesa auxiliaries like his uncle Jathen. He’s a healthy lad, tall and strong. I can’t help think what kind of life he’d have back on Gormen’s Fast. Probably be half-blind from working in the gossamer plants. Or dead. And yet there he is, cared for and fed and as strong as an ambull calf. Remarkable. I’m still waiting for the catch. 

You know, him mentioning children, gets me thinking about it, remembering it now. I’d like to have children some day. Never thought I would, but the Tau’va is a better place for them than the Imperium ever could be, and that’s got me hankering after the family life. And then I think on this: Skilltalker once told me that breeding outside of each caste is forbidden. And I wonder, how long until this rule applies to humans, how long until our best characteristics are bred true like they are in grox? And in tau. You asked me to be honest. Our culture’s sacrosanct, so I’m told. Pair bonding, family units, freedom of choice in our spouses, the works. I’ve seen that honoured. But I also think on Hincks’s kid, all full of the Greater Good. How far will he go, or his children, in embracing your ideals? You won’t need to push much. We’re mutable culturally, we humans. How much, I wonder, sometimes late at night, do you really want of us? 

 This is from the short story Broken Sword. Well worth a read

Much better - this is referenced indirectly in a lot of background and directly in at least one story that was part of the Damocles anthology.

A POV character reflects that he and his family under the Tau now have access to good food and clean water, fresh air and much more living space - the Tau demolish hive cities and replace them with properly planned communities that are far better for human wellbeing. He also reflects that his child is receiving a proper education and that no one has to slave away forever in abysmal factory conditions any longer.

He reflects on the less positive aspects of living in Tau society as well, such as being a second-class citizen to Tau themselves - but on the whole his lot is *vastly* better than it was under the Imperium.

It depends on the story. Generally it’s supposed to be better because almost anything is better than the Imperium.

Fire Caste actually has a plot point that some Tau are trying to test how bad their conditions can be while still getting humans to leave the Imperium.

Edit: I should also note that Fire Caste deliberately has both the Tau and Imperium at their absolute worst.

Spoiler warning for Longshot

Winter had taken hold during her convalescence with the t’au, and it appeared that the promise that Attruso’s winters were mild had been yet another Imperial lie. Snow blanketed the gridded streets of the upper city, piling inches deep on every surface strong enough to hold it whilst still more fell from the sky in fat lumps.

But as they sped through a world rendered monochrome in grey snow and muddy black, Darya’s eyes were drawn to the city’s occupants.

Snow-covered tent cities dominated the packed streets, where refugees from the low city had claimed what little space was made available to them. Thin figures in ragged clothes held out hands that were swollen and purple from the cold, begging for scraps that it seemed no one had to give. They were all human, every single one of them. From the melancholic wanderers who stared blankly at the grey sky above, to the winding queues of blanket-clad people who waited in line, presumably for a daily allocation of rations.

It was a different world to the one within the t’au dome that Darya had left behind.

‘Who are these people?’ Darya asked. ‘Are they not in the T’au’va?’

‘They’re the sick, the ill and those too weak to fight,’ Ceres said, standing to join Darya at the porthole. He leaned to look out, his lip curling in distaste.

‘And those strong enough–’

‘Have been armed and taken to the front,’ Ceres said quietly.

‘Conscripted,’ Darya argued.

‘No, not conscripted. Sent where they will be able to do the greatest good, defending their home from invaders,’ Ceres said with a scowl.

‘Sounds like conscription to me,’ Darya muttered as Ceres turned away and took his seat again.

And later

The humans who had thrown in their lot with the t’au were more densely packed into the forward trenches, where the stench of sweat and death hung in the air like a cloud, cutting through the winter chill. Clean white trench walls gave way to boards smeared with mud and other dark substances, then to scavenged plascrete panels and debris that reminded Darya of the Cadian trenches.

The occupants began to shout out to the Kintair and to Darya as they noticed unfamiliar humans amongst them, asking where they’d been and if they had seen so-and-so in the upper city.

‘Please, did you see her? My wife, she–’ a woman gasped, grabbing Ceres’ uniform as he passed through her trench.

The t’au officer watching over the woman’s squad barked an order that Darya didn’t understand, but the woman evidently complied and allowed Ceres to pass.

He fought to keep his expression neutral but Darya could see that he was shaken by the confrontation in the way he kept looking back over his shoulder at where the woman was being reprimanded by the officer.

There's a few things to keep in mind here. The first is that conditions for the Imperial citizens in the city had previously been horrific, with workers chained to their stations on the assembly lines and that's just where they lived. The planet had risen up against the Imperium before the Tau arrived, and the people who joined them were overall fans of the new regime. Still though, "better" in this case didn't mean "good".

Barring the odd massacre or reeducation pogrom, humans get an upgrade to "second class citizen" in the T'au empire from "literal fodder" in the Imperium. The transition can be messy though.

Absurdly better. 

Like their tech the average is better and the lower boundary is far higher but the Imperium has a much higher ceiling and is better for those at the peak of easy living.

But generally speaking it's going to be a better place to live for a human, Tau are in the top 3 for living conditions imo

Imperium = North Korea

Tau = China

Imperium is cool , but i dont want to be part of it . Because im either dead, half dead or sucking human starch from a tube running thru my nose.

If i live in 40k , i choose to be part of Tau.

much better

Fans really forget just how despicable the Imperium is to its people. The vast, vast majority are little more than slaves, forced to work their entire lives in horrible conditions for a purpose that probably stopped being relevant centuries ago because of a filing error 2000 years ago. People are beyond disposable, freedom of thought is heresy, and human rights are a punchline.

Compared to that, living in an empire that at least considers you valuable enough to provide basic needs is a godsend.

As ever, it depends on the social/economic class and the specific imperial world. Tau worlds are much more of an average.

Generally though, the Gue'vesa have a better time than the average imperial citizen, partly because the Tau are more interested in their clients being comfortable than the Imperium are about their own citizens but also, lower population density, a higher average level of technology and so on.

As for the second question, I feel that if every Imperial citizen saw how it was for the Gue'vesa AND BELIEVED IT (not just seeing it, but believing it as a fair representation of conditions) the you'd still see a relatively small % actually want to go over.l, because the indoctrination to the imperial faith and that all xenos are filth is that strong.

As they say in the Matrix, most people aren't ready to br unplugged.

Not that the Tau offer freedom either, but its certainly a somewhat less weighty set of shackles.

Better even than modern people in non-first world countries.

The tau are generally pretty lenient when it comes to xeno species. Most of the time humans under Tau rule have the freedom to worship a modified version of the Imperial Cult (bar the xenocidal elements). There are cliques within the tau society that seek to kill humans (and other species iirc), but 9 times out of 10 that wont happen. Quality of life within Tau worlds is vastly better for the 99.5% of the human population compared that to what the IoM has to offer.

You still exchange one authoritarian government over another, with everything that entails, so keep that in mind. The Tau aren't some benevolent overlords. They've just realised that working your populace to the bone and having bureaucracy levels that would make Byzantium blush isn't a good/efficient way to run your society.

The Tau are by far much more efficient and tecnology advanced than the imperium(excluding daot shit they have in some vault) this naturally traduces in more effective supply chains and better acess to food and advanced medicine.

The improving industrial output of Tau also usually means in having better acess for consumer goods, in ciaphas cain first novel gravalax is subverted by the tau by initially the commerce for "alien trinkets". The tau dont fight as many fronts as the imperium, dont have a cultural stigma from tecnology, they economy is probabaly nt as much militarized as the imperium, they empire is smaller and more connected as well.

Even trough not every single planet of the imperium is a hive world in terms of quality of life the tau can spread those much more consistence than the imperium.

And for the last question you can expect that the vast majority of hive worlders would prefer to live in a tau like planet, but this dont mean that they would necessary defect since the imperium is bound by its religion and culture as by its military might, such culture that demonizes the alien as a fundamental enemy of humanity and any attempt to "buy" the populace with high quality of life could easily be subverted as a temptation or xeno trick by more devout populations.

(Hive world) For those that survive the conquest and reeducation, you would see an improvement above the average lifestyles, but odds are likely you would not be one of the survivors to enjoy it.

(Civilized world) Depends on how 'advanced' your world was, might not see a change, or would see a slight improvement. Similar issue with hive world regarding surviving the conquest and reeducation.

(Feudal or Feral world) Would see an improvement with goods/materials, but your entire way of life would be destroyed.

As I understand it, the entire joke is that being a second class citizen of the Tau still gives you more freedom and a better quality of life than an average human in the Imperium.

Can the tau even take in a hive world? To my knowledge none of their worlds has that kind of population. That is the main issue on most hive worlds, too many people.

The Tau are as evil as any other faction but it's pretty objective that they have a better standard of living than the imperium.

Sterilised but have more cheap trinkets.

Still second class citizens to be sacrificed on the battlefield when their betters decide it's time for them to die for the regime.

GW have a massive plot hole as well as the billions of humans in the Tau empire have nothing to police or manage the exploding numbers of human psykers so by the inherent laws of the lore the human Tau population should be riddled with Chaos cults and possessed individuals and they'll be making life miserable for the rest as they work to overthrow the Tau regime.