Voice acting always seems like a contentious issue with Japanese role-playing games. Delivery is frequently stiff or obnoxious, oftentimes taking away from the experience rather than adding to it. From the sound of it though, the English dub in Tales of Xillia is coming along rather nicely.
The characters seem very natural, if a little enthusiastic. And apart from the exuberant amount of grunting during battle, the voicework sounds very promising. Still, I'm sure more than a few folks out there will hate it out of principle.