We use Samsung Galaxy Tabs 2 at work in our vehicles that serve as GPS trackers, communications (Skype), and GPS navigators. We've never had any problems with GPS signals, even inside the vehicles, glove compartment, and they have not had any durability problems. They are in faux leather cases.

I also have my own Hinsense 7 in. tablet in a faux leather case with mini-Bluetooth keyboard (from Amazon) that I take everywhere, including thousands of miles in a pannier. No problems yet with it. That tablet can also charge from a 18650 Li-ion battery in a ML-102 or 202 charger, if I do run out of juice.