I prefer PG not to include tracks made by users ever again. Sure it was fun and all, but that last race where you have to go through the river and the rewind couldn't work (like, at all), was frustrating enough. Plus that forest trail didn't help matters either. Going to back to that will just piss everyone off again.
I rather PG stick to what they know best and this is the format for that, plus it doesn't take long to get the new cars either so that is nice as well.
What I DO prefer though, is PG integrating Free-For-All Playground Games into the game like someone suggested on the stream (I salute you sir
). That will make my day!