Well, if you ask me:
Scarlett Witch. She might be the best character in the game at dealing AoE damage, plus she has several useful debuffs for party play (which I mostly skip). Her Combusting Hex ability just melts groups of enemies away like no other. Combine that with Reality Implosion, which deals damage AND pulls enemies (wide radius too) and you pretty much clear full areas by yourself. She also has Ruinous Tempest (another high damage AoE) to top it off. Against bosses or single targets she is not that great, because most move about and resist the pull, so you have to land the hexes ahead of them and don't get the full effect. But, with some attack speed her basic power (LMB) is nothing to scoff at. Her mobility is not good, but she has Flight at least
Storm. Her thunder abilities are kinda like Thor's, but Thor also has some neat melee stuff while Storm obviously doesn't. Her other trees are more of a crowd control set with slows, stuns, knock-backs, etc. and I like that she has a dash. She's a good overall character, but her raw damage doesn't scale as well as with other characters.
Hawkeye. Pretty much what you said. Build attack speed and crit and everything dies. At low levels you have to focus on a few enemies at a time but by the time he gets Triple Arrow and the Tear Gas AoE he manages against groups just fine. Triple Arrow is just an insane basic power. It is free obviously, doesn't have a super big spread so you can get all 3 hits on a single target at a fast rate and all can crit at the same time. It sucks about his roll (now it is a lame stun) but he is a fun character to play overall, and probably my choice for starter character. The downside is that I don't see anyone taking more than those 2 abilities and the roll or the lunge, plus the required passives, which might make him super repetitive in the long run. If the endgame gets significantly harder then he might make use of some of his crowd control abilities.
Thing. Eh... I don't like him that much. I only got him to level 16ish, but he is your basic tank character with shockwaves, ground smashes and auras like Colossus. Not much fun to play by yourself, but good in a party with other damage dealers and ranged characters. There are other better melee guys imo.
Daredevil. I like that he has dodge and movement speed as passives, because it makes traversal and close combat a breeze (you can boost both to like 50%+ with gear and costume crafting). The problem is his damage. He relies on landing a ton of basic attacks that don't feel powerful, and for AoE he only has one ability which has a lame animation, poor range and crap damage as well. I like his Radar Ping ability for the graphical effect (screens goes black and red and debuffs/highlights enemies), and that you can run around and jump all over the place like a cricket on drugs, but you'll pretty much have to hold down the attack button and wait 10 minutes for every minor battle to be over. Against bosses it's worse due to their increased HP pool. He needs a major buff to be useful.
Great breakdown thanks a lot. And ya thats one of my big concerns with choosing hawkeye tho, and from what i've played him too, it seems like its just like using his basic triple arrow like 98% of the time and i was afraid that he would get really boring. And like i said since im going to main Thor i wanted to choose someone that would be a lil bit diff play style and compliment him so thats why i wasnt sure on storm either. But i didnt know SW was soo strong and had such good AoE dmg but im sure thats prob at high lvls tho right. Still cant really decide its so tough, im torn between SW, Storm and Hawkeye >__< lol I do want to play hawkeye i liked him a lot but im afraid he will just get boring, and i dont want to bank on hoping that they eventually change him around again to be more fun lol. It's a tough decision but thanks for all the info ^_^