I've played both and I've liked both. It really boils down to what kind of skills interest you. Ask yourself this question:
"Do I want to gain Full House + Power Charging on Gambler for more AoE?"
"Do I want to gain Volley Kick + Sumo Suit for fast 1-on-1 and damage reduction?"
There are other good skills too but most people compare those skills when deciding. Definitely look at the other skills though.