The problem is that I've already read these stories in the regular Marvel Universe. It's like buying a "best of tape" for a series I've already seen.
Well, with the Crisis, people got over it pretty fast. The problem is that, as you pointed out, DC has done numerous reboots. Now, you have Zero Hour and Hyper-Time and all that crap.
If Marvel would do one good reboot and have the writers stick to it (unlike the mess that the post-Crisis Hawkman caused), people would adapt. If they kept pulling a Zero Hour every five year, then you would have problems.
Anyway, I don't think I'd read Ultimates anyway since Millar is writing it. I'll never read any of his books because:
He's been quite vocal with his Anti-American statements. I won't go into them here since politics are off-limits. But I don't want to support a guy in his efforts to play out his prejudices.
Also, the man has no respect for superhero comics, such as descibing Superman is really a villain and saying, "Could Superman really be described as a hero when all he ever did was reinforce the world's unjust status quo?" and describing Batman as an "Al Qaeda-like figure" (I seemed to have missed the issue where Batman kills thousands of people and advocated the abuse and degradation of women).
On top of that, the guy is just a fruitcake. He's said some really strange things like how he lives in Scotland and has never seen a black person and wants to date a black woman for the "novelty" of it. Er, yeah.