I EDC a garmin when out in the "field" But backup button compass would definitely not hurt.
Agreed. I carry a Magellan SporTrak myself (time to upgrade), but of course, they're battery-dependent, plus some possibility of malfunction of the unit's electronics. In the extreme, if I were incapacitated in some way, a companion might not know how to use it.
My PSK compass 'til a year ago was a button-style, then decided to upgrade to the next level for better reliability, accuracy, durability. Went with the
Tru-Nord 150C for the lanyard/split-ring attachment point. A couple similar from other makers, but they slip my mind at the moment.