Updated 2: I have to down vote the rating because now it keeps having the voice feedback "Connected" even if I'm on a normal non-Wifi call. I'm on my Samsung Note 9/10 and there's no issue with Bluetooth connection from this phone to my bluetooth speakers. Just how this headphone keeps saying to you "Connected" while you are on a call, it is so annoying.
Updated: I had an issue with sound feedback when using the headphone for calling in Wifi app like Viber: usually connection for these types of app is not reliable. Even though my network is stable, the app often reports poor connection - this is issue with the app itself but usually you can still use the app without much issue listening and taking, however, the headphone somehow continuously gives sound feedback "Connected" after 1 few seconds so this is annoying.
Sound quality is just average for music. I use this for calls only so totally fine for me. Microphone is also OK, I got feedback sound is clear and no complaint so far. Quick bluetooth connection when turned on. I have used the headphone for a few hours only so don't know exactly how long it lasts for each charge. Overall OK for the price tag.