So after playing last night and a bit just now this morning, and servers still not being available, I'll reserve full judgement until Online is back, as the game BADLY needs it.
However, impressions based on playing offline are of initial disappointment. The game feels so soulless, just going from menu screen into a what feels like a mundane race against very badly scripted AI is no fun at all. I was expecting several "skill" zones per race e.g. average speed, drifting, per race to liven things up, but so far after around 15-20 races I've only experienced a handful. I'm hoping that more of these get introduced when you are connected, as I'm sure in preview videos there were races were there was a zone every few corners or so? I did one race which was a time trial, and got to 50% and still hadn't registered a single point, not through cocking up, just the fact there was noting to do other than drive flat out! At least throw some max. speed zones in when it is a fast track!
It does look nice, but I'm not blown away like I expected to be. The lighting effects in particular are outstanding, best I've ever seen in a racing game, but take those away and a few other bits and I actually think it looks quite bland? Weather can't come soon enough.
Hopefully Online is fully functioning very soon, and things pick up excitement-wise, but after coming straight from Forza Horizon 2 this feels very average, and definitely not a finished product.