It's probably the best GT game since 3, that is if you ignore the lackluster single player content. Even then, it's not really lackluster imo... just not as much as a mainline GT game.
The biggest thing I've noticed is that the game feels like it was made for car enthusiasts who actually enjoy the act of driving, aka us, the people in this thread.
Intangibles aside, driving is really really fun. Like each car has a very distinct feel and it really does require you to use a different driving strategy(how you tackle a corner, throttle control, braking points, etc) in order to drive it.
I'm not naming any names, but compared to another console racer out there, GTS is leagues ahead in the overall satisfaction for the game. When I got the game last night, I spent 3 hours doing the beginner driving school and another hour playing with photo mode. Meanwhile on that other game, by hour 3 I was already trying to figure out if I could return the game to Amazon since I already opened the game up and all that.
So if you're somebody who really cares about the SP experience, it might be a good idea to wait a bit, but if you're into online racing, or you can find fun in the game through other means, then I say go for it. I don't even have PS+ to play online but I've been having a ton of fun playing the AI and just cruising around(on the DS4 too no less) because it just feels really good to drive in the game.
But more important is this lol: