So with 10 hours played during the last 3 days, I can say for sure that I love this game. I've been spamming offensive heroes mostly (McCree, Tracer, and Genji are my most played), but I've found people like Bastion and Lucio enjoyable even when there are too many offensive heroes. Even the goofy people like Junkrat who I didn't think I'd find entertaining in the slightest were a ton of fun to play.
Right now my favorite character is Genji, but I think he's a bit inconsistent to use every match. McCree has never felt like dead weight once you get used to hitting people from mid/long range with his left click, while Tracer can either be ridiculous or super underwhelming depending on your aim. I'm just bad at Pharah, while Reaper has to be too close range for my liking. Soldier: 76 can be pretty fun, but he feels super vanilla so I've tried to avoid playing with him.
I found that as soon as early access ended and open beta began, the quality of matches went down very quickly. People don't seem to realize that it's an objective-based game and simply run around trying to kill people. I've had so many winnable games lost because my team refuses to try and force overtime. I assume this will get better once ranked comes out since you have to be at a certain level to play ranked, but it can be a little frustrating.
Bastion + Reinhardt is super good, but whenever I've played Bastion with a Reinhardt the Reinhardt will just focus on trying to 1v3 instead after a certain point (whenever on payload offense). I'm probably going to try and play with friends as often as possible when I'm actually playing to win because communication seems ridiculously important in this game. I've also found McCree + Reinhardt to be super good because you can just channel his ultimate behind the shield.
I really wish there was an easy answer to turrets other than Genji deflect and snipers, since Torbjorn and Bastion are currently very good at just camping out and killing people. I don't think I've actually gotten less than 25 kills in a Bastion game since nobody knows how to play against one. Symmetra really feels annoying too when you're a Tracer, but it makes a lot of sense that there's at least one surefire way of dealing with a hero with that much mobility. She just feels especially oppressive in maps with a room that you have to traverse to get a flank (King's Row first point, Hollywood first point) because she just sets up all her turrets and melts you.
I love the extras that Blizzard has been putting out. The backstory of all the characters is pretty interesting, and the mini-movies were all pretty interesting, even if they were kinda cheesy. I'm really looking forward to seeing more of them put out.