OK, so I'm not DC Rainmaker, but I feel that someone needs to more publicly chastise Garmin about the failings of this device and their customer service. Hence, my Amazon review, which can be found here. If you're equally frustrated by the 820, go there and click that you found the review "helpful" -- let's up the ante and maybe Garmin will, one day, become more responsive.
Having said that, I am currently running the Garmin Edge Explore 1000 and find that fixes almost ALL the flaws of the 820 (or, perhaps, more accurately, doesn't INTRODUCE all the flaws of the 820). I can actually recommend that unit if your focus is on good turn-by-turn navigation (and you don't care about not having workouts or more than one bike profile).