I play as heihachi as a main, sometimes Dan or Sweet-tooth. I get 100% dominated by anyone with medium to ranged attacks like that killzone guy, Kratos or raiden. I cant speak for most but I have played Kratos and raiden, and it is unbelievably easy to win, to the point where its not fun. Also some of the special attacks are complete garbage compared to others. Raidens level 1 is better them some lvl 3's.
On a second note, is heihachi grab glitched? When I grab one way he always switches from grabbing infront and to the back. Most of the time its not in the direction you're looking.