MW600 has got all the features of BHS 3000 and more. Been using it everyday for 2-3 hours for almost a year while commuting to work. Battery backup is very good. I get 2-3 days playback time.
Display is a handy feature for configuring 3 devices, FM radio, volume control, playback info, battery level, caller id or number, call duration etc.
Near zero loss of signal. Wherever I keep my phone (bag, deep pocket, laptop at the corner of the room), there is no disconnection at all.
Sound quality: will be almost exactly same as what you hear from your earphone, connected directly to your phone.
But, the bundled earphones need a burn-in time of atleast some 100 hours before they feel ok. They feel like crap out of the box. I use Sennheiser CX-180 or Soundmagic E10 with it instead. Go for it, you won't regret at all.