Seriously Heihachi is rushed ruined in this game... The Circle button do almost nothing. And his level look like a standard attack.. What they have done to a Tekken rep.. Tekken is a psone and Heihachi come from psone.
As a very long time Tekken fan, I can inform you that you are unequivocally wrong.
I played Heihachi only once and already knew that he's actually quite deadly in the hands of an expert. My main for FFA is Radec, my main for 2v2 is Ratchet, but I may actually look into having Heihachi as my main for 1v1. He has an auto setup for his level one if you know how to do it. It's down circle, then while he's charging up, press neutral square and he flings an electric punch forward, making your opponent drop to the floor in a slow manner long enough to launch your level one and get a guaranteed kill. Much like Evil Cole's auto setup with his fire punch.
You can set up his level 1 with forward square. I think it may be possible to avoid but I get people with it all the time.