Originally Posted by
floridamtb
The Garmin is much more accurate with elevation at places other than sea level, even Garmin admits it's way off at sea level. So I can trust it in the mountains of Virginia where the rides start and end at the same spot as well and the elevation is correct, I also used a GPS app on my phone to check elevation when I was at summits etc and it was close to the Garmin reading. But I also had mapped the rides out on RWGPS and the elevation was accurate with is as well. That's why I wish I could turn off the elevation at sea level.
That's my experience also. Though I never used my 810 at sea level, here around my home (~900m) the readings are usually +/- 5-10m apart. I only see more significant fluctuations when I leave home and in the middle of the ride or on the way back it starts raining hard, but that usually happens typically in the summer, when you get those intense and quick summer downpours with quite a barometric fluctuation.
Other then that, the last time I checked (about 3 years ago) Strava was about 10% more generous in terms of average speed, distance and altitude when compared to an Garmin eTrex, my then brand new 810 and a Echowell cyclocomputer. And at least here, of the people I follow through Strava, it's really easy to see who uses Strava on their cells because of the complaints of lost data and/or weird rectified routes on their ride maps.