Jabra aimed for the best of both worlds with their BT8010 Bluetooth headset. On the one hand, it's a relatively compact mono earpiece with an LED display and large clickable scroll wheel so you can scroll through your recent calls and contacts list and place/receive calls and adjust the volume without having to reach for your handset. The BT8010 even has a vibrating alert function if you're into things buzzing against your ear and head.
On the other hand, the BT8010 comes with a second earpiece that connects to the main unit via a wired mini-USB plug. Hook the two units together and you've got yourself a stereo Bluetooth headset for use with A2DP-compatible musicphones. The idea here is that you can buy - and pair - one headset but only have to wear that second earpiece when you're listening to music. During the business day, keep the main unit on hand. After work when you're headed out for a run or want to listen to tunes on the train home from the office, plug in the second earpiece for luxurious stereo.
In theory it's an interesting idea. And in practice? The BT8010 generally performed well but suffered from a few key design flaws. Most notably, the speakers on the earpieces are quite large. In fact, I had a difficult time getting a comfortable fit. Maybe my ears are a bit on the small side, but I found the 8010 uncomfortable to use for any extended length of time ? so the headset was fine for voice calls, but not so great for extended stereo listening. Second, the 8010's multi-pair functionality is limited to two devices. This wasn't a huge deal to me (I paired it with a handset and also with my computer and that was enough), but some folks might want a bit more flexibility.
But the 8010 paired easily with my devices and sounded quite good during voice calls and pretty good while listening to music. When connected to my Apple iPhone, SE K790a, and a few other test handsets, call quality was clear on both ends and wireless range was a little better than average for a mono earpiece. Used as a stereo headset with the 790a and a few other music phones, audio quality was pretty good if not quite in the league of in-ear headsets like the Motorola S9. The BT8010 lacked particularly in the low-end registers.
Of course, the 8010 provides a level of flexibility that a headset like the MOTO S9 doesn't. With the S9, you're bound to speakers in both ears and a plastic band wrapped around half of your head whether you're listening to music or talking on the phone. The Jabra BT8010 lets you ditch the second earpiece and connecting cable unless you're actually using it. It's a clever innovation, and if you find the actual earpieces comfortable, I could see really liking the design. Unfortunately the 8010 didn't quite fit my ears well enough to make me fall in love with it as a Stereo headset.