Another happy wahoo convert here. I used it off-road on the BB200 and on some rides more local to me (in suffolk). Generally it’s fine as long as you have a route you want to stick to.
It’s not great for “having a look around” as while zooming out is possible, detail is lost and you can’t pan about.
It’s comes with maps of everywhere and (in the UK and France at least) that includes off road ROW.
Creating and syncing routes with Ridewithgps is a doddle.
Three final things that the Wahoo does better than Garmin, 1. when you pause/stop a ride none of the options are the fatal “discard ride” option.
2. On the one occasion I’ve managed to run it flat, I plugged in a battery pack and it booted up said “recovering ride” went from 0 to 100% and carried on if nothing happened.
3. My 810 would start shutting itself down when on charge and it reached 100%. The wahoo just keeps on trucking.