Brilliant game - definitely one of the best sims out there. Wasn't quite as good when I first got it (had some AI problems) but over the years the updates have definitely improved it.
The car selection is pretty good, as is the track selection, all of which are very well reproduced.
The car physics and feel is brilliant, doesn't feel over exagerated or anything but still a challenge (but more realistic feeling that GRID Autosport for example).
Support for controllers is fantastic, I currently have a Thrustmaster T300 with the T3PA Pro pedals and a TH8A shifter all plugged in and working with no issues, and the in-game controller setup works very well. A decent sim rig definitely adds a lot of value to this game.
Although it may seem difficult to begin with, once you've got used to it and began making your way through the career mode it becomes incredibly satisfying, and the point where you drive your first real racing car on it (the first few stages of the career mode have you drive road cars like BMWs) is geniunely exciting, it doesn't feel like you've just driving a more powerful car, you really notive the better brakes, handling, and acceleration, but if you're driven and got used to the cars up to that point it doesn't feel overwhelming and difficult either.

10/10, easily!