The gameplay stuff seems to have been mostly covered - I love some of the UI alterations.
Like not having the tuning shop anymore, it can all be done from the setings menu, and adding NOS, which I haven't used yet, but that'll be interesting later on for sure. The bar shaped layout of the main segments is so much easier than the scatterboard one of old, its still left, right, up, down, but its linear, so you know what your button presses will do.
I like, weirdly, that all the cars are in the same place, it sort of eases the fact that standards are in the game, and you can better keep track of which cars you own and need, its not a hunt to find them all. The garage filters seem much easier to use, easier to toggle between them all as well.
The licience test being integrated is actually a really great idea, I'm kind of skipping through the driving segments, just doing enough to get the starts (for now), until I advance to the S licience, or whatever the top one is, then I'll come back, but it extends the length of what is effectively 'A-Spec'.
I like how somehow, I know the physics have improved, but it isn't an out of this world experience from my knowledge of GT5, which is great, because I can get in the game and drive cars I did before in a very similar way, if not an almost identical way, and acheive the same results, my driving instincts have very little in the way of change required for this game, very pleased with that.