Okay first off, I m not having NO PROBLEMS with this game in terms of stability and performance, nice and smooth here, also I was reading EA fourms, and it seems ATI are not the only once with stability issue some people with Nv have had problems with it and Nv cards.
It is a good game, but I do feel that it can be made better, I don't think the game is at its full yet of what it can do and yes you can see it in the game, I think pandemic wanted something more maybe they will put it in(yes I know they are gone but the core IP remins with EA) or it will be left up to the modders ethoir way I feel they like it too was rushed out.
cars, well I thought engine upgrades and a well stuff you may find in GTA4 aswell but maybe I was wrong, unless it does I just have not got that far yet, I mean one car upgrade is that it? as for the controls, Ive only died cos of me being a noob and set the game to hard and stopped in the heat of battle or I missed a tele line
also about the stealth, it does work, however I think pandemic/EA made that bar fill up wayyyy to fast