It was better in XIII-2, since they removed the godawful, potentially game-ending lag that came with switching Paradigms in battle. The number of times I got cheap-shotted by bosses because I had to watch my party members twirl their weapons...

...that aside, I didn't mind the Paradigm system, but it was a definite step backwards from the Gambit system FFXII utilized. The AI in XIII was diabolical, and when you consider the multitude of options the Gambit system had, being limited to six very basic roles was very...restricting. It worked well enough in the game, but it was still pathetically simplistic.