The ONLY thing I am Really let down of is the usual bad replays :/ Why cant Turn10 add really Good effects like motion blur DoF, good cameras etc. (Helios????!
Real-talk: Some tracks have much better composed viewpoints for replays than others, and a lot of framework content carries over from game-to-game. For example, Suzuka and VIR have some great angles/tracking. I can't say the same for a few of the tracks carried over from Forza 5, the production for which was a race to get a completed title out for a hardware launch.