I'll get this out of the way first. Just like with most Blizzard games, the balancing is absolutely atrocious. Some classes are far and away stronger than others and it's not even close.
But, it is really fucking fun, and I went into it thinking I'd hate it.
Can't see myself playing for very long after release, because of how many hours I put into closed and open beta, but if you're looking for a new TF2 guys, this is it.
Three price points. Regular 40 bucks, Skintastic 60 bucks, Collectors a bit more.
I think that's fine, no extra levels or extra maps or any bullshit like that, just a few skins which a lot of people probably couldn't care less about. 40 Dollars for essentially a newer Team Fortress is a bit steep in my opinion but holy fuck the game is fun so I'm going to get it anyway.
The frustrating part is that nobody wants to play healer, so you can either choose to suck it up princess and pick Skaterboy (easily the most overpowered support), or just pick Soldier but honestly against half the scrubs in open beta having a healer wasn't even necessary since you can just destroy them with positioning.
I'll review the classes I've played, implying anyone's going to read it.
Tracer: Pretty much unstoppable in 1v1 situations. Mcree is her natural enemy and should be avoided unless you get the jump on him or it's a doubleteam. Genji is easy if you bait out his counter.
DIEDIEDIE: Ridiculous damage. Lack of range isn't a problem since no map is super open with lots of close range
Soldier: Vastly underrated. Average damage at every range is actually a very powerful weapon you can use to exploit, since most other characters have very specific ranges.
D.VA: Terrible as a tank, disgustingly overpowered as an Assassin. Severely needs a nerf.
Reinhardt: Overpowered for escort the convoy.
Bastion is an unfun piece of shit that runs rampart through bad teams but can't do anything against good ones, so he's in the awkward territory of a pubstomping Rikimaru. Can be used to kill tanks amazingly fast, but again you'll probably be picked off before you get a chance against top players.
Widowmaker: Sniper.
Hanzo: Midrange sniper and high damage.
Genji: Unkillable on PC, and fun as fuck.
Torbjorn: Garbage and requires ultimate to be effective. Once enemies know where a turret is, unless you're playing against horrible players, it's pretty much dead. Turret damage or health needs a buff. His standard weapon though is actually pretty strong.
Winston: Decent
Junkrat: Hilarious, but decent.
Roadhog: Decent+
Zarya: Amazing offtank with insane damage.
Mercy: Good for pubstomping with a bastion reinhardt combo.
Rollerbladebro: Overpowered, by far the best support and it isn't even close.
Lightomancerturretgirl: Useless as main support, good off-support but there are better choices. Basically a meme character that can work but needs more to close the gap.
Mcree: best Duelist in the game since he has flashbang and insant reload with dodgeroll. Easily combos most characters in the game. Desperately needs his team to understand how to help him with positionblocking though, since his lack of mobility combined with his skillset makes him absolutely fucked if he gets zerged.
Ballhealer: He's awesome until the other team has a widowmaker or hanzo. Their ability to one shot him severely impacts him, which is a shame because he'd rival rollerderby if he had a bit more endurance. His damage is bullshit and his healing is quite good. High Risk High Reward support. I can see him being great. If the other team doesn't have a sniper then use him for the lels.
JUSTICE RAINS FROM ABOVE: She is a very, very hard counter to most characters in this game. Hopefully your years of Quake and TF2 have paid off if you want to use her effectively.
Mei: Funnily enough she might be the best tank killer in the game, yes even better than bastion. Purely because she can freeze them so your DPS can take them out. Wall is devastating if used correctly, and devastating if used incorrectly. Strongly requires communication. Iceblock is great. No real negatives, she's a very balanced and annoying character.
So if you bothered to read that you'd say "but all the characters are good, you said they were imbalanced!" and that is blizzards biggest problem with most games. Characters are so overpowered that the characters that are only good fall by the wayside and become effectively useless. The most glaring examples are that there is no reason to use any of the support characters other than Lucio. Bastion is too horribly countered by too many characters to be used effectively as anything other than a gimmick pubstomper. Many ultimates remove skill entirely by being uncounterable or unavoidable. Hanzo get his ultimate way too often, and even though it's not as effective against good players, it makes him one of the best defenders in the game with his ability to zoneout offense repeatedly and reliably. Widowmakers ultimate needs a nerf or honestly to be changed entirely, since a good Widowmaker on a team that knows how to defend an area and block off assassin routes is too unstoppable without adding a teamwide wallhack.
TLDR: Fun as fuck, a lot of balance issues, too many clear choices for characters. After sinking a disgusting amount of time into closed and open beta and racking up far more than is healthy of a playtime I'm still interested enough to buy it