The sound has rich bass, a nice mid-range and not-to-harsh highs. Great for working out or casual listening. Again, you get to set the tone, so it's up to you.
Build quality is very good. No complaints there at all. The headphones snap into the charging case with little magnets so its easy and sure.
Connectivity issues seem to be fixed with the latest firmware update, notified through the app, and was quick and simple.
I'd buy these again.