Other than the improvement in cut-scene as well as the ingame-graphics and the change in the battle-system, I'm also very fascinated with the new approach they've taken with voiceacting in FFXII. A large part of the cast have been given British accents, and Balthier is no exception. Below is information on both his english and japanese voices.

Background: Gideon Emery was born in England on September 12, 1972 but grew up in South Africa, where he studied fine art and drama at university level. His career began with commercials and later evolved into standup comedy, earning him a regular spot on the sketch comedy show Not Quite Friday Night. He's also done movies, stage performances, voice acting for other videogames, such as The Matrix: Path of Neo and Goldeneye: Rogue Agent, as well as musicwork.

My opinion: Yum! British accents are a win by default in my book! At first I thought he sounded a little too deep for a 22-year old, but I got used to it just after a couple of lines. It seemed necessary to make him sound more mature and streetwise. Even though there's a huge agedifference between Balthier and Basch, they do speak to eachother as equals while Vaan is the youth of the male group. Square Enix certainly picked the right voice-actors to make that come across and sound natural.
Emery's voice is perfect for Balthier's personality. He can really deliver those stoic and cocky lines but the caring and soft ones just as well.

Background: Hiroaki Hirata was born on August 7 1963 in Tokyo, Japan. He has previously done alot of voiceacting, mostly for japanese animated series(One Piece, Digimon and Naruto being thre of them) and dubbing actors in japanese films. As far as I can see he's kind of the official voice of Johnny Depp in japan. He's dubbed Depp in 13 movies and in the Square-Enix game Kingdom Hearts 2 where Jack Sparrow makes an appearance.