Re: GPS as an option?
The things are well 'ard!
We've been using them for half a decade, mainly with Linux installed. They are very rugged (used for lairage management in slaughter houses and for cool house management after the slaughter line. They are exposed to all sorts of crud and they are just washed down with a high pressure hose after the shift.
So often as they are dropped, I wouldn't think an android in a waterproof case can keep up. My Galaxy was dropped from 1M onto marble tiles and, although the screen remained intact (it lande glass side down, but completely flat, so the shock was distributed evenly, pure luck), the antennas stopped working. Dropping that thing from 1M onto concrete won't even make it blink.
We haven't had any reclamation from our customers, and some are still using the devices that were delivered half a decade ago.
The only thing I've seen that was tougher is the old Husky line from the 80s. One of our field engineers got stuck in a field, stuck his Husky under a rear wheel of his Mercedes K-Wagen and managed to get enough traction to drive out of the field. He walked back, picked up the Husky, washed it off in a near-by stream and carried on working. Try doing that with a Galaxy Tab, waterproof box or no.