I'll try and post up more details later but on a recent trip to Thailand I mounted my Samsung rugby pro on my bike and it worked for about 4 hours and then the vibrations must've killed the military spec phone.
Just a warning to throw out there. FWIW I was riding fast freeway miles on a thumper - KLX250 w/351 kit which seems to vibrate more than stock. No rain, I didn't have it plugged in and all ports were sealed. I imagine it'd last a lot longer on a twin...