PGR3 is more towards arcade racing, its nothing near a driving simulation and shouldn't be compared to GT4.

On the other hand, GT4 is more towards the simulation route but not too extreme, I personally preferred Forza Motorsport over GT4, which should be the more appropriate game to put into comparison, unfortunately not many people actually play the game. Many might not even heard or played or saw it before, and all they know about racing game is Gran Turismo.

Driving simulation fans would really wanted to try games like GTR2 and TOCA Race Driver 3 for a more authentic driving experience.