I think the key to T4 is to not have crazy expectations. I saw it last night and I didn't expect much more than good action. And I thought it was awesome. Granted, I was also pretty baked, but to me it was a really good movie. Obviously there were pretty big plot holes and some of the stuff was a little ridiculous, but IMO the movie made up for that with non-stop action. It was fantastic. I actually recommend seeing this in theaters rather than DVD because on DVD the action scenes won't be as good as they will on the big screen.
Don't go into this movie expecting Citizen Kane. Go into it expecting a decent story and tons of stuff blowing up and you won't be disappointed.
(For best results, see it while inebriated)