Poor attempt to clone Strava amongst others putting in the social elements, and even trying to add segments just like Strava.
Their software general seems quite poor.
Many firmware issues with the Edge 510, though getting better, but they still can't get Bluetooth to work. A number of odd quirks and bugs, some of which can trash rides which is not acceptable, though can avoid them (e.g. disable auto power off if you pause the ride, else you lose the whole thing).
Connect is a rubbish site generally. Doesn't even hook up with their own upload plugin and it's awkward trying to find the manual upload option.
Garmin Express... avoid at all costs! This is top of my suspect list as to why I and many other end up with all position data lost as it appears to trash the .fit files. Either that or it's the 510 trashing them on power down. I don't power down now until I have uploaded the ride and I have uninstalled Express. I copy the .fit files off via USB before I upload to Strava, though I use the Garmin browser plugin with Strava and seems okay.
Take a look at the Garmin forums. Full of issues and complaints about their software.