I didn't like it very much, but I'm really pretty biased. Were I a fanboy of anyone/thing, it would be Nobuo Uematsu.
Final Fantasy XII, the entire game, not just the soundtrack, went in an incredibly different direction than earlier Final Fantasies had. Despite that, it has been received extremely well, both by long-time fans as well as new fans to the series. I'm just not a part of that demographic. I couldn't pull myself to finish the game because it just didn't feel like Final Fantasy to me.
I'm not saying it's bad. It's just not for me.