The problem I have when the App is the downloading of maps. Either the app crashes, or in the case of the other night it caused a massive panic in my phone. Went into a reset loop and had to completely restore the phone.
Also, until they add the ability to scout on your computer and sync waypoints (theoretically this summer) its tough to scout on a touch screen.
The GPS is going to be more reliable for service. If your phone quits, due to lack of service, it will not be good.
You don't use "service" on your phone, you're only using GPS.
Jeff/Randy11 can the app be pushed to card storage? I've got a few coupon codes from the Rendezvous I have yet to take advantage of.