Still one of the best racing sims around: impressive driving physics, detailed car set-up options, awesome sound and plenty of difficulty customizations. Plus it still looks good, you can adjust the graphics in the settings (car details etc). There are settings for a wheel set-up (force feedback etc), however you can play it with a Xbox 360 controller as well. You have four driving perspectives to choose from: cockpit, over the hood, bumper and third person. There are weather effects in the game.
It has all sorts of assists: AI difficulty, damage realism, automatic gear shifts, brake and steering help, tire and brake wear, as well as indicative arrows for corners and gears. So in theory anyone can play this game. You can adjust everything of importance: gears, tires, brakes, differential etc. The AI can be adjusted with impressive range: timid, clean, realistic, aggressive etc.
To sum it up: great driving physics, awesome sound, nice selection of tracks and cars. GTR gives you an immersive GT experience.