I have been playing 2hrs each race in both categories and several tracks: Formula Raceroom and Prototype Raceroom, so in one hand, as FR respects...I can stay longer on track than AI before time of changing tires and fueling, what makes too easy beating AI. In the other hand what PR respect, happens the same of FR... plus, the half of AI, race dumb, so it's kinda like playing againts GT if you pretend those bad AI belongs to. Hope the performance of AI can be improved soon