I've got second hand Sony Ericsson MH1 for half price. Not so special, good sound, not better than the old HPM-82 or MH810 for example. And the lack of a clip for hanging on the neck piece is obviously a disadvantage! The free is constantly slipping down and pulling the ears - very annoying!
The lack of separate buttons for changing the music tracks is also a disadvantage - music tracks are changed with continuous pressing the volume buttons of the handsfree's remote control, not with separate buttons like on the HPM-82 or MH810. But it seems that this is due to the 3.5mm jack cable-number connectivity limitation. The MH810 has some additional ports on the side of the 3.5mm jack, which allow it to have more buttons on the remote control, while MH1 doesn't have them on the jack.