On a recent trip I had some cases when my wife's 810 navigated correctly where my 830 totally failed. Here's a couple of examples:
1) We rode a route that two loops that intersected near the finish (both start and finish are in the same location) point. Near was 0.1 - 0.25 miles distant. At the beginning of the second loop my 830 directed me back to the finish and my wife's 810 correctly routed us along the second loop. After riding along the second loop about a half mile I stopped and re-started my route and my 830 again directed me back to the finish. I road a few miles and tried again with no joy. Finally at the point where we were furthest from the start my 830 decided to navigate correctly.
2) We did a ride with 4 loops including a lollipop (out for a mile, do a 3 mile loop then return on the mile segment) trail that literally looped back to itself with no side trails. At every loop the 810 correctly navigated and the 830 failed. I have my screen set-up so I can see the distance to the next turn and while on the loop section of the lollipop my 830 counted up not down as expected. When I got back to the common segment my 830 went from 3 miles to go to 0. At every turn, to a new trail, on this route the 810 correctly navigated and the 830 did not even prompt at every turn.
Both devices had the same Openstreetmap files that I downloaded a few days before we left on our vacation.
NB: Garmin you're supposed to improve your product each generation not make it worse.
