Saying that Forza isn't a consle racing sim comparable to Sony's GT series is nothing more than biased nonsense, especially if the person doing so, ethomaz in this example, is proudly sporting a Gran Turismo avatar for all to see. Sorta discredits any anything that attempts to come across as 'fair' opinion wouldn't you say. That would be like asking some a lady dressed in military femininst gear and carrying a 'Woman's Rights' picket sign if she thinks Tiger Woods is a good person.
No offense ethomaz, but when you're so clearly on one side of the fence, no one's really going to accept what you say an anything more than overblown, fanboy ranting. Certainly not fact.
There's two types of physics for console racing, arcade and sim. Play Need for Speed then play Forza, play Project Gotham then play Forza, Play Dirt then play Forza.... for all a consoles technical shortcomings compared to it's PC brethren, Forza is a racing simulator just like GT.
As for the OP, don't forget the massive amount of hype shoveled our way by Turn 10 leading up to the release of Forza 3. There's a few developers out there who are world class at over-promotion and second class when it comes time to deliver; Lionhead studios, THQ to name a couple..... and Turn 10. For example, 'the definitive racing game of this generation' shouldn't get released minus local leaderboards, there's really plenty of moments where they sorta juggled the ball while making Forza 3, if not completely dropped it. Hopefull 4 really will lay claim this gen's racing crown, shouldn't be too hard, just don't get blinded by the guys over at Turn 10 while you're waiting for it.