update : Dual shock 3 controller is awesome
GT5P is a bit of a disappointment... i didn't know prologue didnt have the car modification ability... which was basically one of my favorite things about gran turismo 4. Fortunately, the graphics are nice and the cars are super sweet . its worth 40 dollars imo, but no more than that. Had i paid a full 59, i would have been pretty angry at the lack of substance. Hopefully they will add some more tracks as time goes on as well, id like to have Tsukuba and the nurburgring atleast...
There is the sweet novelty value of having the ISF in the game for me, its alot of fun driving a car that looks essentially the same as what I have in my garage; and the inside car camera view is pretty awesome, due mostly to the great detail of the car interiors.
Overall though, id have to say that GT5P would be better as a rental then as a purchase... im probably going to have the game beaten by tomorrow, and the il just have to work at getting all the cars lol. If you rented it, you'd probably get your fill of gran turismo in the one week you have it. Of course, if you are a major car fanatic or GT fan then I guess you're probably going to buy the game regardless.