i have a cheap one that my friend gave me that he got for free, and the quality is awful.
i think with BT headsets you get what you pay for, but then again, I think voice chat on the PSN may just not be implemented well.
when i play on ps3 w/friends, usually we just turn on our 360's and get in a party and chat using 360 instead. the chat on 360 is ssssoooo much clearer.