A bit of a thread hijack. Having established that the Touring can be used and charged at the same time, the question is - how?
I see from the manual that the USB port is behind a little door on the bottom edge of the device, facing you as it's mounted. So theoretically on an out-front mount you might be able to squeeze a cable in. But if it was stem mounted I'm kind of doubting that you'd be able to keep it mounted and get the door open and a cable in there. The door looks like it's made from soft material.
Does anyone do this, or do they just wait for a break in the ride and do the charging then?
Do people really get 15 hours life (as the manual says) out of it? Even on a night or winter darkness ride with a lot of use of the backlight?
Next question. All my Garmins (non-bike) have a little eye through which a lanyard can be fitted. I can't see one on the Touring. I'd be wary of mounting an expensive GPS on my bike without a secondary means of attachment in case it comes free from the mount. Yes, I know a zillion cyclists already do this, but I'm an old worry-guts.