I've been playing GT5P around at my brothers who has the same setup as Mr Lattes, proper racing frame seat/G25 1080p PJ etc.. and I have to say that graphically GT5 is superb, no doubting the models are briliiant, and the lighting is very very good.
That's not to say FM2 is rubbish graphically, from a photo mode/replay perspective it's a little disappointing.. However playing a game, bumper cam, it's still mighty impressive..
Physics wise, FM2 is for me still ahead of GT5P, specifically there seems a siight scriptedness to the handling in GT5, making it very predictable, playing back to back with FM2 with similar cars, and FM2 seems to react far more dynamically, every bump/kerb/undulation/throttle input seems to have some little effect on the handling that can make controlling the car that little more challenging..