Used the Garmin i3 this morning for a meeting out in Hayes...
Not sure about fixing to the tacho glass - vibes and that.. so stuck the unit in the plastic envelope of the BMW tank bag angled towards me. Secure and waterproof
Worked a treat - its a bit further to glance down than I'd like but was ok in practice as the display is pretty clear. You can just hear the nice lady's voice when in town, on the open road forget it...
Having never had sat nav and having spent many hours circling my intended destination previously, I am well impressed.
Should be ideal for my main use which is being (no longer) lost in London and the SE so battery life (6hrs) should never be a problem and planned routes irrelavent.
And its tiny which is brilliant.
Ade