First of all, lip sync is a issue of the game being localized. The game itself is fixed to work with the japanese voice overs, not the english. The programmers don't alter the animations to fit the english voice overs for the localized releases of the game, so they only have one animation that only fits with the japanese dub. This is a common thing among video games and is not something that is easily gone unnoticed. Therefore the japanese voice overs should have better fits the lip sync. Let's be honest though, the only impressive character animations is during the fight scenes, other than that is repeated loops of a talking animation with no intention to sync anything.
Though I play the game with the english voice overs some games that don't bother to do any, I know is always the main part of criticism of many things from Japanese media being localized. Rather than start a debate of which is better or more tolerable, I use English simply cause it allows me to easily understand things rather than need to read subtitles within a short time span during the progressing story that I can just hear what they say and process the context faster. Is not a debate whether one is better by opinion of how the actors sound but by being able to have less difficulty in processing information. Perhaps when the New game plus arrives, I may download the 800MB+ Japanese language and give it a try, besides the names may be different. Pyra being called Homura, I doubt is much, but unless we knew japanese then it wouldn't matter much.