It's awesome. The graphics are incredible, I don't know how they can make a PS2 do such things when every other game PS2 comes out with has such awful graphics. The gameplay is incredible, although I'm not a super hardcore street racer kid, or a veteran of racing games, I found the gameplay to be very detailed....well except the fact that cars still bounce off each other and other shit and never break but...oh well.
....and the cars. GT4 has like every fucking car ever. From your old civic, to old muscle cars, to a 49 beetle, to the first mercedes ever (1886!).
Definately an awesome game, even moreso if you're really into cars...too bad I only rented it..