I play Genji alot and don't think he needs a buff, imo he's one of the most difficult to learn characters but the most rewarding to play. But with this ridiculous new Bastion buff, I'm finding it hard to kill Bastion, he can heal through deflect and run away in recon mode. IMO Genji is no longer the hard counter to Bastion he used to be but my teammates still expect me to melt him at will, sorta how people expect 76 can kill Pharah easily when its actually really hard against a good Pharah.
I love playing Winston too but he feels underpowered but in Korea he's considered one of the best characters, I think he's deceptively hard to use at an high level. The key is using the leap in, shield and leap out at the right time, getting angles, etc. He's similar to Genji in that his value is not that apparent to his teammates, hes a disruptor.
But overall I'm disliking the new balance changes, Mercy's rez is too powerful now imo since she and her teammates and invulnerable now for the first few seconds, and bastions ironclad passive needs to be toned down to 20-25% max.