I thought long and hard about this - and then I realised I still play GT3, and I haven't had Pro Race Driver out for ages - in fact, I play TOCA2 on the PC more than I play Pro Race Driver.
Graphics were disappointing, and the driving model was a bit of a disaster - to the point that it ruined the racing. TOCA2 had a decent physics model and it had fantastic racing - big braking duels, blocking by the AI, going around the outside, payback punts - it was the peak of the series, IMO.
If only GT3 had great AI - even the lack of damage would be okay then...
Mind you - the signs from GT Concept were promising - I had a bit of a duel with an Astra where it actually put a couple of good moves on me - including one beauty around the outside at Autumn Ring that would rate as the best I've seen in a Gran Turismo game.