My opinion sides with Robin's. If music only makes up roughly 5% of your overall sessions, I don't see a solid reason to spend more money on a speaker that you really won't use to it's full potential.
IMHO, when watching a movie you're not really listening, looking for or noticing fine detail since your eyes and brain are focused more on what's on the screen. However, two channel critical listening is a whole different experience.
If money is not much of an issue and two channel listening may become more of a priority in the future, I'd also recommend a pair of HT 1's. While waiting for my HT3's to be born, Jim was kind enough to lend me a pair of HT 1's while I waited. They are an amazing speaker.
Good luck,
Mark