My local computer store was having a sale, and so I bought a new set of earphones, and here is my mini review.
The set is Meizu EP-51. These are low cost (about $30 US) in-ear bluetooth headphones. You can find them here.
Despite being wireless and cheap, they sound pretty good. They do not sound tinny or distorted like cheap earbuds. They don't have a lot of bass like some earphones (like the Sennheiser CX series), but it can be heard. The high end is also a bit lacking (or is it my failing hearing?). Some delay is noticeable when using them for videos. Good isolation, so you don't have to crank up the volume. 8/10
Takes a while to get used to them, but they are quite comfortable. I use the large size ear pads (you get four sets: small, medium, large and extra-large). The ear pads have those wing-like things which help keep them in place when you move around. When exercising, I recommend putting the cable behind your ears because it causes cable noise if you don't. 7/10
Very poor. Sometimes the sound can cutoff just from turning my head, with my phone (Nexus 6P) in my left pocket (the receiver is near my right ear) or covering the phone or receiver with my hands a little. The sound can also cut off if I leave the phone on the ground and move about 3 meters away. A single wall can kill the signal entirely. I have to keep the phone close to keep it working. 3/10
They have a tiny 60 mAh rechargeable battery. It is charged using a micro USB port on the receiver. Charging takes a long time, 1-2 hours. It is rated as 6 hours battery life, and I've not had problems with it. It's good enough. The earphones cannot be used while charging. 7/10
In the box you get the earphones, 4x pairs of ear pads, a (very short) micro USB cable, an instruction manual and a carrying case. They sound good and great for working out. All that for $30. Good value. 9/10
I think these will be my go-to headphones for exercising. They don't fall out, they sound good, and and are light weight. Highly recommended. 8.5/10