Well, my iPhone sucks on coverage. I workout in a state park a few times a week and I know exactly where my coverage works and won't. It takes me between 1-2 miles longer coming out of there. I have been to the tops of mountains and into the Grand Canyon with friends with other networks and they have voice and text ability and AT&T won't. I have to use their phones.

I have tried the 'send text with no service' thing to see if it would send through anyway on a weak signal and it has never worked. Tried maybe 50x. On the iPhone the text will display w/ a red dot with exclamation point indicating that it did not go through. I have to resend it once i get coverage.

I carry a SPOT2 with custom message or set up codes for what each OK Message means; for example if I am going to the park to swim and then ride my bike, the first OK my wife gets means I am no longer swimming. Second OK means I am done riding and heading home. Then she knows I always call her once I am back into range.