I hated it because of how utterly incomprehensible and illogical it was. Iron Man goes to Xavier's house, finds out that it's emply, and then...decides out of the blue that this means Xavier has joined with Magneto.
Wtf?
And then Magneto attacks the Ultimates, kicks their ass, so...because of this, Captain America decides that he's going to take down the X-Men. Not Magneto, but the X-Men.
WTF??
Way to make the Ultimates out to be arrogant, senseless bullies even more than usual, Millar. As if fighting themselves wasn't enough, let's have them start hunting a bunch of scared teenagers for no discernable reason at all!
And then the actual "war," which didn't even happen until issue four of the entire series, was a complete letdown. Cyclops wasn't there, Iceman wasn't there, Xavier and Jean were taken out by a bunch of psi-scramblers, so...instead of a fight of the Ultimates versus the X-Men, what we actually get is a fight of the Ultimates and the entire SHIELD personnel versus Wolverine, Storm, Colossus, Beast, and Kitty. What??
Oh, and Millar just couldn't help himself and just had to make a few of the soldiers bigots.
Oh, and Captain America beats Wolverine by being a cheap bastard. Goody.
Oh, and then the way that the X-Men win is that Iceman just shows up and beats everyone.
I've never regretted buying a trade more than I've regretted buying this trade.