FWIW in my experience with Edge 530, TR gives a lot higher elevation gain. On flat routes around here with two freeway overpasses and elevation between sea level and 60’ above sea level:
- Garmin/Strava/TrainingPeaks will show about 200 feet
- Strava and TrainingPeaks elevation corrected will show about 100 feet
- TR will show about 400 feet
Something like that.
Extreme example from a coffee ride recorded on Apple Watch:
less than 100’ of climbing turned into 1941’ of climbing on TR.
Again that is crazy extreme and some artifact from how Apple Watch records and TrainerRoad processes.
Garmin vs TrainerRoad is a lot closer, with TR being a little too high on flat rides.