On my PS3 I've spent the most time playing Kano, Cage and Reptile. I think I've got the 24 hour mark for the 3 of them; Quan and Sektor were nearly there as well but then I stopped playing online. So I dunno. I put about 6 hours a week into the game now at max, online plateaued for me and I just try to learn shit from offline casuals now. Obviously I never play Kano anymore because well...he sucks.
In terms of online I think I've played something like 7,000 matches; not that I learned much from it and I mostly consider it a waste of my time. Anyways, I've been playing the game since it came out, but yeah...Kano and Reptile were mostly hurpa durpa mode online for a long time. "LOL KNIVES! UP BALL! TAKE DAT RAIDEN U SUX!" "LOL ELBOW DASH U KANT PUNISH ME! BALLS BALLS SPIT! D4 ACID HAND!"
