I'm quite unhappy about Valley. Not only does it feel rather like Stadium, no exciting brakes/drifts, instead some ice-skating on dirt, but all the same crashes and weaknesses of the editor still exist and the look is not nearly as exciting as one might've extrapolated from Canyon, if you asked me, really. And they have a beautiful engine!
Worst of all, however, there was no way of testing it before buying, which is plain ugly. Nadeo really goes for bad habits on this one and I sure hope they recover from such strange arrogance quickly. They've got in essence a great thing going, but somehow, something happened to them. Customers?
If I had a wish, it would be to take Canyon to the next level, really. Noodle with the physics a little to give it some more weight and corresponding grip, but not as sticky and stopping as stadium and valley; spend your years with figuring out more exciting crash solutions where appropriate (head first into walls, this sort of stuff or anything that warrants a respawn), splashing water would be nice. But most of all fix the damn editor and media tracker. You still have to reload your map, if you wanted to deal with a replay in the MT. It still crashes arbitrarily, if you add things (like an Image, as I had it just now).
Without a doubt it all is a matter of opinion, but- for what it's worth- this is mine.