Until we see more footage of them compared in game side by side it's tough to call, me personally I preferred the Drive Club trailer it shows more in car in game footage, also it's a new IP which makes it more interesting.
Forza 5 did look fab, the metallic paint on the McLaren is very good, the overall attention to detail in both games is amazing, next gen is looking good. :)
Forza 5 was in game footage according to this.
Yep, they're real. Xbox boss Phil Spencer confirmed in an interview this afternoon that the footage you saw for Forza Motorsport 5 and Remedy's Quantum Break this morning are running on Xbox One dev kits. Not renders or some other trickery, you skeptics. I know some out there were questioning some of the screenshots and footage from this morning. Stop. They're the real deal.
http://www.destructoid.com/forza-5-quantum-break-footage-from-xbox-one-dev-kits-254220.phtml