Aight, let's do this!
Writing stuff in the order they pop up in my head
I had tons of fun playing it until 07:00 Swedish time (that's about 4½ hours of gametime). Took me some getting used to the controls. At first I was like "why is dodge on C!? oh... kinda hard to slide with dodge on CTRL". Most ppl I've played against are kinda oblivious to what's going on, and no they're not bots, and there were a lot of noobs.
You unlock all weapons and attachments by doing "Challenges", that are separate maps that you need to complete in time. 4 different challenges in 3 difficulties each. They're actually kinda tutorial-ish. The first star challenges are easy, and 2 star a bit harder. 3 star is just for leaderboards and prestige. This system is great since it lets pretty much anyone who's good unlock everything within the first halfhour of playing. You can even do them with friends.
Weapon balance I don't have much to complain about. Haven't really tried that many weapons, but I've never felt like "OMFG WTF HE JUST RAPED ME!" and if I did it was a Heavy with a Machinegun outDPSing my SMG.
SMART works really good, but like everything else in the game it takes some time getting used to.
Bots are as stupid as all reviews have said, but I don't play singleplayer so... Only time I've encounterd bots was teamballance or challengemaps. And some players are just as stupid.
Abilities are unlocked with "level coins". You get 1 each level. New abilities for purchase are unlocked at every rank (level 5, level 10, level 15, level 20). Ability points can be reset by paying 1 level, but levels are gained pretty quickly anyway. You can either specialize in 1 class and unlock everything for that class, or spread your love.
That's it for now. Like I said, so far I'm enjoying it! Now off to play some more x)