This is what a racing game should be.
First, this game is hard. I mean really damned hard. You will need to put in about 30 hours or more (maybe 60+ hours) before you get decent (not great, but decent) at controlling one car on a few rally course.
Second, it is rewarding as hell. Once you get decent with a car on some of the courses you'll be having some bad a$$ high speed rally fun.
The graphics are absolutely amazing. The price is decent and well worth it. The sounds are very good. The physics is realistic as hell (thus why it is so difficult to get good at). The car selection improves with time as do the courses.
The game is still in beta but it runs like a polished professional release game and it is updated periodically.
Anyway, if you like racing games, especially rally type games, you should enjoy this once you have gone through the near vertical learning curve.
As far as controllers are concerned, you are really going to want a steering wheel controller for this game, however, a lot of people can't afford that. So, if you are going to go with a gamepad controller I highly suggest the XBox controller for windows PC. The Logitech gamepad controllers are not good on this game as the analog sticks are not sensitive and have dead zones that make the game extremely difficult to play.
Regarding cars; There are a load of cars to purchase using funds you win by playing the game. The variety goes from the 1960's to the 70's to the 80's to modern super rally cars including crossrally and uphill rally cars.
The courses vary as well from asphalt, concrete, light gravel, medium and small gravel, dirt, snow, ice, and slush and are usually a mix of three or more per course. All road surfaces handle differently and are very realistic.
Codemasters have done a superb job on this game and it is absolutely stellar.