OK, I've finally had enough of this unit, and the constant software updates that don't seem to fix anything. I'm running 6.50 after a master reset and yesterday tried to ride a saved tcx course built and transferred from ridewithgps.com. Super annoying. The turn notices show up late, literally after I'm into or through the intersection. As a result, a few times I went off course and the darn unit recalculated -- notwithstanding that I had recalculated turned to off both in the profile and for the course. And if I tried to check where I was by zooming out from the map, the redraw is painfully slow and the map then jumps and loses my position, so it's completely worthless for this purpose. And the gradient display continues to both lag and be inaccurate. And, regardless of which sensitivity I put the touch screen on, the number of missed taps and swipes is ridiculous.
I like the unit's incident detection and integration with the Varia radar, but enough is enough. My 800 was much better in every respect mentioned above, but its battery no longer holds a charge long enough for more than a 4 to 6 hour ride.
Got home and ordered the Wahoo Element Bolt. Anyone want to buy a used 820?