After putting about 6-8 hours into it today with a friend my opinion on the game is that it's not great, but not awful. If I had to rate it on a scale of 1-10, I'd give it a 7.
People are being a little hyperbolic of the game. The mechanics of the game are decent. The game is tactical. If you're playing 8v8 and you don't have 6 solid players on your team then you're going to lose. The game requires extreme coordination, and you can't be a hero. Bots are useless, if you're in a match with bots just get out.
Completing objectives is difficult, but with the exception of a few maps they're not mind numbingly hard. The classes are varied enough and all have useful buffs. Turrets seem pretty weak, but they can make nice traps. The weapons are balanced. So much so that it doesn't seem to matter what weapon you choose, they all do around the same damage. And that's kind of disappointing to me, I don't understand why an SMG with a drum magazine is just as effective as a crazy chaingun.
The parkour is definitely important, people just don't know how to use it effectively with the maps yet. There are great places that lightweights and middleweights can hide and sneak through the map with. Customization is cool. It's fun to mess around with.
In the matches I got in that were lag-free I had fun. It was even more fun when I wasn't playing with idiots.
So the main mechanics of the game, although different from any other FPS I've played lately are good. The glaring flaws with the game aren't from the game itself, but the way matchmaking is handled. No lobby system is

ing retarded, and the way parties are handled is just as bad. In a game that REQUIRES teamwork I can't believe they bumbled that up so badly. If they patch these things in, the game easily becomes 8.0-8.5 for me. It's a headache the way it is.
And I don't care what they say, there's no singleplayer. Just multiplayer with bots (which by the way they need to have a humans only option for multi). This isn't a negative for me, because this game does have solid multiplayer.
It's not GOTY. Not even close, but it's still a good game. If they fix the network issues and matchmaking/lobby system, it'll be even better. It's not as bad as people are making it out to be, it's just a different kind of shooter with some really obvious (but possibly fixable) flaws.