The included double O ring mount is good except it won’t stay in place when wet or on rough ground. You can glance down at it easily but it’s not too much of a distraction in your eyeline either. If you crash or drop the bike it’ll rotate out of the way or come off.
I’ve been using the 76 Projects top tube mount which is also good. Stays in place, quite a sheltered position but will snap in a crash or if you knee it too hard which is good to save your Garmin’s tabs. But I do clip it with my knees reasonably often, half removing the rubber case from my 530 or half rotating it out of the mount. Also not that easy to glance down to check the map at descending speed on offroad terrain, at least with how quickly my eyes can change focus nowadays. No good for eMTB though as the display is on the top tube, and the orientation is wrong for sticking it to your handlebar.
Some of the lights (Magicshine) have Garmin style clamp mounts giving the same position as the O ring mount. Not all are actually Garmin compatible, and they don’t have that sacrificial insert part to break in a crash instead of the tabs on your Garmin.
Anything in front of the stem, too distracting. On top of the stem or top cap, too vulnerable. Stem spacer mount turned to the side, orientation is wrong.
There is a Varia mount for a 31.6 seatpost which would probably fit a 31.8 bar, has a bit of an angle to it but not too much. Maybe ok if you clamp it lightly, and that’s your bar diameter.
Any recommendations ?