I've probably played more Overwatch than anyone here (beta key) and I can tell you that its not perfect, not anywhere near. There are some huge balancing issues (Bastion, Reaper, Roadhog, etc), as well as lack of any "real" content. Its a glorified TF2 clone, but it does so with a myriad of unique characters. However, the balancing issues are too glaring (and I'm not just talking about Soldier 76). That coincided with bad team work and you have a very grueling time. Unlike TF2 wherein games can be won without medics, you need healers on both sides in OW.
This was going to be a major problem out the gate, as less went into the rock/paper/scissors format of the game, and characters just had ridiculously OP specials and or moves. Blizzard is known to have problems with balancing in general so people will more likely go through phase after phase of patches just for dmg and defense alone. After 100+ hours I dropped the game for Battleborn, I'll take substance over style any day of the week.