I have a Garmin Quest which is old now but still useful.
Good points
Preplanning routes on PC is easy and quick
Vast range of high quality mounting options. egRAM and Touratech do dedicated ones for Garmin. Someone earlier in the thread said they were unhappy with their mount, but this is very much not my experience.
Easy to switch between bikes/car/cycle
Easy to use without voice commands
Battery life is enough for a long day's ride
Clear display
Waterproof (Scottish Highlands. September. Need I say more?)
"Where am I" function very useful for finding parked car/bike
Bad points
Mapping SW update policy is quirky, and updates expensive
Slow to search for places when on the move
Buttond not, "glove friendly"
Hope this helps