After Graces f, I didn't think I would like a TP combat system again, but Xillia 1 was really fun, and Xillia 2 topped that and is now one of my favorites. It took me until my second play-through to really get a good grasp on the battle mechanics, but once I did it was so much fun. It completely broke me from free-running, and I love side-stepping so much because of it now.
Zestiria is weird. The game was really fun at first, and theoretically should have gotten better with more skills and abilities... but the AI just completely ruined that game for me. Partner AI is woefully inadequate (seriously, I had all my characters set to interrupt casting, and instead of going up to casters and using martial artes to cancel spells, they'd use hidden artes which made them cast faster instead), and enemies were so incredibly cheap. Oh, here're 6 casters, and their synchronized spell damage can kill a person in one hit, and you only get enough time to stop 2 from casting. Good luck! That too easy? Here are 8 slimes with no weakness that have AOE attacks that instantly stun you. Enjoy! Want to cure petrification? Too bad! (I had to solo the entire two-gorgon battle because the AI immediately got petrified, and never got attacked again to die from it.) I have never been so frustrated with a Tales game as I was with Zestiria (except maybe the bullshit balloon mini-games in Abyss and Hearts R), and it was 100% due to the awful AI.
I should go back to Graces f to get a refresher on its combat, because I remember it being incredibly fun, but as of now I like Xillia 2 a bit more, if not because I like the characters more. The high-five and Leia's "Boom!" from the Ludgernaut gets me every time.