OK, first impressions. Very-high-quality sim. Load times suck, but the reason for them seems to be to set up absolutely everthing up front. There is no hitching or dropped frames during racing. Very smooth high frame rate always. The simulation seems to be quite thorough. 4 tires are modeled, which believe it or not, is not always the case. (The old shortcut is modeling one tire, with pivoting around the car's center of mass. I think TDU does this.) The cars' behavior is believable. For details, I recommend
the Gamespot review. It seems to cover my experience with it pretty well.
I never played Forza 1, so I can only compare FM2 to the Gran Turismo games. I'd say that it does quite well in that company, with much superior graphics all around. Cars and drivers are modeled in great detail. Strangely, there is no cockpit view. There are 2 chase views, hood view and bumper view. I prefer the hood view anyway, although I'd really like access to max realism (i.e., in the driver's seat). Other than this, I have no complaints about the driving views. In fact, the game options offer one mind-boggling possibility: connecting 3 X360s somehow to provide a wraparound
3-screen view of the action. For the gamer who has everything, there ya go.
The controls feel very good, much better than TDU's. They are versatile, even allowing for dead-zone adjustments of all analog controls (triggers included). Steering input corresponds to tire response always--none of the infuriating lag found in lesser input algorithms (such as TDU's).
As with the GT games, there are a gazillion cars available. These are split across racing classes, and can jump from one to the other with upgrades which are at least as varied as in the GTs. The more adjustable parts you add to your car, the more you can tweak it for each individual race track. I have stayed away from this so far, since unlike GT, I can't find an easy way to do pre-race test runs. I think what I need to do is go to each track for free runs, from another menu option. That's indirect and confusing, so in that sense, GT comes out way ahead. The cars also have a performance number which can vary greatly within each class. I guess the object is to maximize that number for whatever class you want/need to use, without going over (which would bump the car one class).
As the review points out, the backgrounds are somewhat sparse. But they're not bad at all. I definitely prefer steady high frame rate over lush scenery any day, so I can't complain. There are lots of spectators jumping, hooting and hollering, so it's not like they were hurting for headroom in the unnecessary niceties department.
Unlike TDU, this is strictly a racing game. There is no map to freeride around between the race tracks and events. There isn't even a map, period, which GT has. All you get are menus with all the different racing places, restrictions, and options. You can choose to be based in North America, Europe, or Asia. This determines what cars will be available to start, and which need to be unlocked. As with GT, there is a career mode and an arcade mode. Career is what you would expect. The incentive for arcade is to unlock a lot of cars by winning races. Those cars can then be used in that mode and in multiplayer.
One final complaint is that the instant replays kinda suck. There is very little in the way of fixed external cameras. Most of the choices are different close views of your car, which you can rotate with the right stick during the replay. The auto mode is hit or miss, usually miss. With such lovely car models and high-quality display in general, this is a real pity. You can save all replays, as in GT. I've already eaten up about 40 MB of HDD space with these. You can also take still pictures from a replay, and upload them to the game's website.
That's about all I can say at this point. TDU offers more overall immersion and fun. For serious racing, FM2 does a much better job.