The good is that they are light, offer multiple fitting options, provide great sound quality, and have a relatively sleek appearance.
My experience: I've always wanted a bluetooth headset, so when I got these I was super pumped because I'm on the phone roughly 3hrs/day for work. On my first day I put my old plug-in buds away and had these guys ready to go; first call comes and it's my boss, and the call doesn't connect properly. I couldn't get it to answer using the phones. After apologizing and explaining, I try again on my next call, same thing. Later that day I gave the instructions another read-through and then it worked out the next time.
My difficulty: Even still, I don't think the ON/OFF nor the sync functionality is clear for connecting via bluetooth. I never know when these things are ON/OFF and it's hard to tell how to connect them. I guess I just hold the button down for ten seconds and then hit connect on my computer, but it's not crystal.
Maybe I need to give these more patience, but for now, I stick to using them for running/working out, rather than work calls.