My Garmin and other brand trail units are far more reliable than my Android 4.1 phone with GPS app. The dedicated units simply always work. It is not uncommon for the phone to lock up a few minutes after enabling GPS. Sure, this could conceivably be fixed with software or a different phone model, but these issues are moot for the dedicated GPS units which never fail. While in tricky terrain I am not willing to even depend on the phone as a backup. Instead, I take a real old dedicated unit. BTW, I use free open-source maps on the Garmin. These tend to be updated every couple of months. Same maps can be used on the phone, for that matter.
Where do you get the open source maps that you use with your Garmin?