I like the music, personally. It's good, adds a distinct feel to everything, but unfortunately nullifies immersion. It tells you what you're supposed to be doing. Whether that's worrying or not, exploring or not, fighting or not, whatever. For my first 12 months of playing this game- on and off, not constantly- I had the music in-game going, even swapped the default Battle tracks with a Heavy Metal (or something) alternative to get the blood flowing better in combat. An adrenaline boost, to add to the feel.
Adrenaline, eh? Don't need music for that, when silence and chance will do just the same. Last week, while listening to something in WinAmp, a radio station, talk show basically, I load up the game, turn off the game's music... and trek around the Isles, looking for something. A Scalon, tricky things, was waiting for me, invisible. With no "enemy radar" to let me know it's there, I about broke my desk when it screeched and appeared out of nowhere. Was about ready to jump out of my chair, that's how sharply it shocked me.
So, yeah... the music is good, but nothing beats nearly shouting in terror, or at least surprise, at a pixelated critter... even if it WAS a Scalon... they're disturbing enough to look at as it is.