I have these for training sessions and use them sometimes when walking the dog but want to be more aware of surroundings. For these purposes, they are excellent, providing a good blend of external sounds. Great for phone calls too and easy to put on with one hand if you need to - and less easily mislaid than buds!
As mentioned, Bluetooth is rock solid and works well for two devices. Battery life and charging speed are good.
For music listening they are OK.
Customer support is good too (more of a query than a problem in my case). I've had mine and used daily for 6 months. If the emphasis is on the training side then I heartily recommend.