I used to be a Hanzo main. I'm lvl 94, 56 competitve rating, over 20 hours of using Hanzo. I've come to the conclusion that he is a very ineffective hero that relies on luck and in poor enemy positioning. He is not a sniper, but more of a stealthy assassin. His DPS is extremely inconsistent, and a lot of the times it's like having 5 players instead of 6 because he is not pumping any damage.
Another thing that has made me phase him out in favor of more straightforwards characters is the fact that his counters are often picked as they have become staples to the meta. Heroes such as DVa, Winston, Tracer, Reaper and Widowmaker are ubiquitous nowadays, and they all make Hanzo's life a living hell.
So, I benched him in favor of Roadhog, McCree, Junkrat and Widowmaker. Sad because I had a lot of fun with him at low levels.
Opinions on Hanzo?