Don't have a Garmin, just a cheap cycle computer from Walmart, but the way I see it is, it would be 1 less thing mounted on the bar and thus room for yet another thing mounted on the bar.

My little cycle computer mount is curved to fit the bar. I have it zip-tied to the stem which puts the curve 90° to actually fitting. It is mounted crooked but I have 2 lights mounted on the bar and my bar ends made me push the grips, brakes, and shifters in towards the center which leaves no room to mount the computer with the 2 lights. I would like to get a real single bike light (mine are 2 flashlights) and a bell for riding on the trail for alerting those I am passing rather than calling out close enough for them to hear but too close that I startle them (mostly seniors either riding really slow or walking side by side.) I don't really have room right now to mount a bell because of the flashlights.