Garmin just replace my 520+ for a BT chip failure. I pre-ordered last year and it worked perfectly for the 10 months leading up to the failure where I would have to re-pair after every two or three rides. I sent an email to support detailing the problems and what I had done to troubleshoot, and they opened an RMA without any further questions. I bought the 520+ after 7 years of flawless performance from an Edge 500, but today, if I had a do over, I'd probably buy the Wahoo.
FWIW, the Livetrack feature has always seemed to work just fine, and even when I've dropped phone connection mid-ride, the livetrack has continued through the automatic reconnect.