There's a downside to moving from Strava on your phone to a Garmin. When I ride with my Strava-using friends, the same Strava segment appears to be a little shorter for them than it is for me on my Garmin 820. Even when we're riding side-by-side, they usually get credit for a time maybe 4% to 5% faster.
We're not sure why this is. Maybe the phone is timing them off of cell towers while I'm being timed off the satellites? Maybe Strava is giving their users a little "boost?"