Bluebuds X.
[Edit:] Mine proved to be defective (the microphone didn't work) and I'm still waiting for a replacement.
[Edit:] Replacement sent.
[Edit:] Replacement received.
It really works well. The connection is a lot more stable than with the Jabra Clipper I also own, especially outside, and having less cables to fight with is a blessing. I still wish for bigger tips, though. Maybe I'll try Comply tips, but the maintenance (i.e. replacement) cost of foam tips is a little bit daunting. Getting custom silicone tips is also a possibility, but the angle would have to be just right for the earphones to be comfortable and not protrude too much.
[Edit:] A couple of months have past.
I've bought three kinds of Comply tips, all L-size, and hitherto tried two. One (the "sport" one) was too small. Another (the "round" one) fit better than the original Bluebuds X tips, but it's barely big enough and I can still lose the seal, depending on head/jaw motion.
The replacement Bluebuds X still works fine, in spite of my wearing them at the gym and sweating copiously. The sound is good enough that I'm now doing most of my listening on them: They've become my commute earphones.
My opinion: It's worth the asking price.