I had a Garmin street III on my last bike and it was fine. On the SE I bought the new 2610 with the touch screen. I like it much better. Works fine with gloves on. Water will not be any problem.
I installed it with power from inside the fairing, and have the sound going into the AUX in the Harley sound system. I run down the road with the GPS on and the CD going. Than when I need the GPS voice the just flip the control on the bars from CD to AUX
( 5 times gets you to AUX) and I can hear the GPS, than when I don't need it one push gets you back to CD.
I like using the Harley sound system, that way I can adjust the vol for the GPS and I can hear it on the road, you know how the wind can be at at 65mph
It worked great on the Posse ride this year, 7800 miles and never made a wrong turn.
Found food and gas any place.
Dean