For defense, I love playing as Ana. He damage is pretty decent and keeps their heads down. If you want a good quick heal from Ana, you want to use her canister. The canister just feels wasted if you try to use it offensively. It's basically a stronger, swifter version of 76's healing thing. If you can keep hitting an ally, which isn't THAT hard to do, her healing output is definitely much greater than mercy's. She does suck against roadhogs though. her best bet against him is to tranq him and let someone else take care of him. Her mobility really does suck but when you find a nice perch (which is hard without wall scaling or jumping), she can be pretty devastating. It's actually really nice that her rifle still works well even when you aren't scoped in.
Reaper- reaper is basically easy mode if you wanna go in for attack and kills. Phase in and out and get lots of kills. I rarely find a good opportunity to use his shadestep, but he's great for taking a platform above people then jumping down on 'em in an ambush. Plus, he heals himself with the tears souls of his dead enemies. There was one match where we were getting massacred at the beginning and couldn't even get out of our spawn point, even with myself as Rein. I switched to reaper for the first time in a long time and just started killing them all and pretty much solo captured the point to start the payload rolling. And basically outplayed and killed the two enemy reapers who were a huge part of the reason we were penned in in the first place.
Reinhardt- definitely a must have on most modes, but especially an attack and escort mission. Most times sticking with one of these guys is the key to victory. his projectile is rather lacking, but getting that pin kill with his charge is just satisfying. little punks who stare and you through the shield, thinking you aren't gonna do a thing about it.
McCree- I played him quite a bit a first, cuz I was getting some good accuracy shots and that shit just kills fast, but I feel like his rate of fire is just too low and fanning the pistol feels like you lose a lot of damage output per shot as well as all your accuracy. His ult takes much too long to set up and more often gets me killed than the other way around. And one of his moves is pretty much wasted on a rather lame roll with too long a cooldown. Also, his stun grenade only just lasts long enough to get one shot in, and that's just bad tbh.
Pharah- I didn't like her character design at first but after getting killed by her a few too many times I decided to try her out. And holy shit does experience as Benedict in Battleborn really pay off with her. I've already got her trophies for knocking people off the stage with her little pushing blast and getting 4 kills before touching the ground. Her liftoff is just great for approaches and escapes and a direct hit just does so much damage, while hitting right next to a player doesn't seem to do all that much. While not easy mode like Reaper, she nets me a lot of kills on most maps and often lands me PotG's. Like that time I got boosted by anna and just wiped out the entire team, including torb's turret.
DVa- I played her a lot more in the beta. They definitely changed her shielding move and I'm not entire sure how those new mechanics work. Her suit explosion has ridiculous range to it. I'm just not feeling her this time around.
Soldier 76- just a completely solid character. His primary fire is a bit inaccurate for my tastes though. His primary fire does relatively weak damage and you can't make up for it by getting headshots because the inherent accuracy isn't good enough. Otherwise, he's pretty good. I like his ability to run. everyone else feels slow as balls.