Being a fan of the first two FlatOut games I was hesitant to buy this game, since it is Early Access, and I try to avoid this type of games, but in the end my fan part won.
First of all, what is good about it? Car destruction is amazing, it is the most beautiful destruction model I've seen. And even though I have a pretty weak GPU (GTX 650) this game runs pretty smooth (there are some FPS falls once there is a ton of stuff flying around, but the game is playable during those). Controls are nice, graphics are good. But what pleased me the most is the fact that they actually have a tip for you, when creating a server, on how fast your Internet connection should be for a certain amount of players. Thanks a lot for this, Bugbear.
Now, there are some things that are, for a lack of a better word, bad. A lot of features are missing (that is obvious they will be added, since it is Early Access) and not a lot of servers available (again, this is only because it is Early Access, and not too many people have bought it).
In the end, if you want to have a great time on 5-7 tracks with less than 10 cars, I suggest you buy this game. It is really fun, has great optimization and a fun "sneak peak" which allows you to spawn in the middle of a "playground" where you can reduce your car to a 1/10th of its initial size, by smashing it in a lot of fun ways.
If you are sceptical about Early Access and want a game where there are no grey buttons which you can't press since those features aren't out yet, I think it's better for you to stay away from it for a while and check back in a year or so.
PS I would like to know why someone dislikes my review, I don't mind dislikes, but please, leave a comment on what the problem is, just so I can focus on this aspect more. Thank you for understanding.