I'm going to disagree with everyone else here and say the original.

While in a lot of ways, Duodecim is better, but it also ruined my two favorite characters/playstyles.

Terra is now one of the worst characters in the game. They heavily nerfed both her range and power.

EX Mode is now completely useless. Don't bother boosting it with items or anything. It's a rare match that lasts long enough to even activate it, and it doesn't last long enough to get any real use out of if you do manage to use it. So Bartz's Goblin Punch is now worthless as well.