The lack of tracks is my biggest concern with Forza 5. There HAS to be more tracks released either free with updates, such as next week's rumoured update, or paid DLC. I really hope that the Forza team wanted extra time to make more tracks up to the standard of tracks released with Forza 5.
My only other moan on Forza 5 is the whole next driver target system. You get told a few drivers and their times to beat before the race. During the race, should you beat the target time, you get given the name of the next target driver, but not their time. How do I know what their time is if I can't remember it from the screen before the race?