I have an Edge 820. The first day things were a little tricky. The Connect app on my phone kept telling me that the device needed an update before I could add anything to it, and to check the Connect website. The Edge 820 would tell me to check the Connect app to turn on Wifi. There seemed to be no provision in the app itself to upgrade the GPS's firmware. ...those sorts of oddities.

But then something cool happened: I plugged in my phone to charge, and plugged in the Edge 820 to charge. While they were charging the phone app sent an update over to the GPS. The GPS, once fully charged, displayed a message that to complete the upgrade I needed to unplug the device. I followed that instruction, and the device updated. After that both the phone and the GPS needed to have the bluetooth paring removed, and then they needed to re-pair. At that point they were both using the latest versions of the software, and were fully compatible.

Now everything works as expected; as it should. ...maybe even better than expected. I discovered just yesterday that even if I create a route using the connect.garmin.com website, I can then tell my phone to send it over to the GPS. I don't have to install software on my computer. Any ride info that gets recorded automatically syncs with my phone's Connect app, and then up to my Garmin Connect account. Strava also just works. The on-device routing works well enough, too.