I just complained here about how I had fits recommencing my ERA 300 stereo pair with Gen 3 sub.  Took me about 2 hours of fiddling, factory resets, etc.  Finally got them back, but in Bluetooth was only one speaker playing.  Major disappointment and not happy.  Went to dinner and came back.  Bluetooth functions fine now and the sound from both Amazon Music and iPhone seems to be so much more dynamic and punchy.  Maybe just my imagination but that’s OK.