DO NOT buy the $150 Tri-Port model. While the sound is fine [for me...not looking for BoseBashers to come out of the woodwork
], there are better to be found for less money, but the main reason to avoid these is that the headband has a cheap plastic component that splits with minimal torquing. Bose has happily sent me two replacement pairs so far, but this latest set is also cracked (the ear piece will slide completely off). They seem to last about 6 months or so.
I think I'm going to buy something else. Even though I can get them replaced again, it just isn't worth the hassle. These things never leave the bedroom. I only use them while watching DVD's on my PowerBook so I do not disturb my wife while she reads. It's not like I'm wearing them while I'm moshing, for cripes' sake.