Hey there, 
I've got ahold of an early access license to test the game before release. I'd suggest to wait and not buy the game. Here's why:

The game crashed 3 times before I managed to run a simple session. I tried GT4 on Nordschleife because that's what I know the best. First thing I noticed was that it looks like Roblox but still only runs at 35fps max. . The physics didn't seem to bad at first, though the 'cold' tires were already on temperature after turn 2, meaning the actual feeling of cold tires was already gone. The traction control system feels unrealistic because it feels more like a stability control from a street car, which corrects the car's trajectory instead of just cutting the power- like it would do in a regular GT4. The ABS felt like it was non-existent. I didn't feel the ABS even when it was kicking in. Force feedback was okay-ish, except I basically couldn't feel curbs at all. Even though my wheelbase was tuned to 10nm, it felt like 5nm when driving and suddenly having a 12nm snap when losing grip (breaking your wrist). The track felt weird, can't really tell why. The Nürburgring GP track looked decent to an extent but as soon as I turned onto the Nordschleife I noticed that something is off. It's way too narrow. At least that's what it feels like. Maybe the barriers are too high? It just all feels very unproportionate. The inside curb exit Hatzenbach was too short, outside run-off of exit Brünnchen was wrong and too narrow etc. . Overall the elevation and track orientation felt off. Some parts there was way too little elevation, for example from 'Hohe Acht' onwards until 'Planzgarten'. The AI has no spacial awareness. Like not at all. Like the devs forgot to implement that. I was side by side with another car, inching in front and the car turned into me with all it's strength (we were on a straight) just because it wanted to follow the racing line.. which I was on at that moment. The cars selection is big and ranges from MX5 spec to GT3 and 70s Prototypes. Track selection features a few very known tracks like Nürburgring, Spa, Monza, Sebring and else. Though for some it seems like they couldn't get ahold of a license, naming Monza, Imola, Silverstone and others like something else but their track names.

Obviously this is my personal experience and subjective view of the game and you shouldn't only rely on this. I'd suggest to watch video reviews to form your own opinion. 

@72taron Thanks so much for sharing your thoughts and early impressions. I really appreciate the level of detail you went into here. This gives me a much clearer picture of where the game currently stands, and it’s genuinely helpful to hear from someone who’s actually tested it before release.

I’ll hold off on buying it for now and keep an eye out for more reviews as things develop. Thanks again for taking the time to break everything down so thoroughly.