I didn't mean to imply that Forza 2 wasn't a simulation, because I feel it is. But I felt Gran Turismo is even more detailed with it's car customization options; in how I've read the lead developer is crazy about getting every detail about the cars in the game right. There have been a couple of Forza's released in the time since there was even one GT.
As far as 2K9 embracing arcade elements, I don't feel so. I think they've tried to make the game more authentic, tried to further distinguish players via attributes and individual dribble/dunk packages, they've worked to make the entire game experience feel like a real game from a presentation standpoint, etc. Online still has it's issues, but it's so much more playable than it was last year. They were the first to do online leagues and to my knowledge I don't think there's another sports game more customizable than 2K9 is (or it's top 2-3, at least). I just don't get why the game gets condemned as a whole for the few things some people don't like