Can’t speak to Garmin, but I love the Humminbird.
I gotta say, it would be nice having the preloaded maps (if they are any good).
The awesome thing about the Hummingbird for me is the autochart feature. I’ve never bought a Lakemaster because I’ve mapped all the lakes/spots I fish myself, probably to better accuracy. That along with side imaging in the summer have helped really narrow in on “the spot on the spot.”
I also love being able to split screen a flasher/sonar with the GPS mounted on the wheeler or walking with the auger when searching for fish. Not having to flip back and forth between screens, gloves on and off, etc.
Not sure how often I’d use a touch screen ice fishing.
I have no doubt they’re all great units. Those are just some things I like about the bird. Garmin may have the same functions. When it comes to the flasher/sonar function when you’re just planted with a transducer down the hole, the brand doesn’t matter at all anymore in my opinion. Everything from bird, Marcum, Vex, Garmin are all good these days.