Pascal - Garmin 500 here with 1 1/2 years of use. Love it! Have mounts on four bikes, road, back-up road, tandem, and MTB. Tried it on the track bike but LA Velodrome is too encased with concrete to get a signal. Probably would work at San Diego and Encino but for now I'm enjoying riding the track with no data other than split and lap times from the facility timing system.
HRM strap is a bit of a bother. Most mornings it starts out reading fine in the garage, keeps tacking out the driveway and first few hundred feet then it drifts steadily north from 90 - 100 all the way to 240+. It will then drift around for quite a while, as long as ten minutes, then once my chest is good and sweaty it will magically start recording properly and be spot-on the rest of the ride. Well unless I catch some serious cold-dry air on a long downhill run then it dries out and starts the process all over again.
However, if I start the ride with a vest, windbreaker, or jacket it will read properly the entire time.
No amount of pre-wetting the contacts seams to make a difference for me. If it isn't warm enough to have good body sweat at the start expect to have some issues.
Welcome to Strava. Now you will need to get one of those tee shirts that says - Strava made me Dope!