TomTom GPS vs Garmin

[AzBob_imp]

I'm glad to see this post.....I ran into problems using my Android when riding east and south of Knoxville, TN in the national parks there, including of course, the dragon, skyway etc. I mounted a water resistant 12 volt / 5 volt USB on my handle bars and ran the wires under my tank to my battery. Worked out great except when out of cell phone tower range.....so I was wondering if a truly GPS unit would work up in those hills and mountains?
I use a "Riggs-Nelson" tank bag I saw first on this forum that has a phone and GPS tilt up zipper pouch with a clear window that works pretty good...I could see it pretty easily when riding, but sometimes I would be happy to pull off just to see where I was at.
I was lost once going up out of Gatlinburg, TN (it was a STILL a nice 60 mile ride on extreme curvy roads) and the cell phone was not much help....a GPS unit would have been nice!

A GPS (or a cellphone with the maps downloaded previously) works perfectly as long as it has clear line-of-sight to the sky. The only reason a phone GPS may not work so great is usually the map data are downloaded dynamically, so if the data connection drops (usually due to not having cell towers near by or being blocked by mountains), then, while the GPS chip and radio in the phone can tell you your coordinates, it can't plot them on a map because it doesn't have and can't get the map data; dedicated GPS devices always have the maps on the device.