This is a holder for an outdoor unit (in my case Etrex30), is the least I can expect that the holder fulfills "Outdoor claims".
She does not in my opinion.
The latching between Navi and bike mount is stable - the fixing by the cable ties on the handlebar / stem not, in spite of the elastomer is to increase the friction between the handlebar and mount. Once a downhill is a little rougher my Navi twisted the handlebars. It's frustrating !!!
By design on my MTB is mounting on the stem is not possible - because the problem would probably occur less because no transverse forces are so strong.
It when Garmin least additionally a screw holder (as for the old equipment, eg Vista HCx) would offer would be nice. So to me, the impression remains one wants to stick with a possible low-cost and universal part only optimize his profit margin at Garmin.