Was able to put about 1.5 hours into the game before having to get ready for work. Very happy so far with what I have played. I did the first 3 mandatory races, Circuit of Americas was seriously giving me problems. Playing on Highly Skilled difficulty, I had to restart the race 4 times, but on the last try came in first really easy. Like other Forza games, once you are ahead, it is pretty much a lock unless you massively screw up. I was able to charge to front about mid-way through the first lap and never looked back. Not sure if it was pure luck or having to run the course 4 times before and learning it, but felt good to finally beat it and come in first.
I messed around with the menu's, very damn slick. Hitting "LB or RB" moves you from tab to tab, which is not explained that I can tell. But very impressed with the presentation and the entire UI system they put into place. I also went and downloaded/bought all the free cars just to get that out of the way.
I only had time to do a quick 1 lap race on Prague just to see how it compared to F5 version and I think it looks a lot cleaner and some mild changes here and there made it a better looking track overall.
That is all I had time for sadly. Cannot wait till after work tomorrow to really dig into the game some more.