Although what I have to say on this topic has nothing to do with the debate currently going on, I will say that I carry a SPOT with me most every hike I'm on. In an emergency, I'd rather have a shot at getting help than no shot at all.
That being said, I just thought I'd tell you all that a friend of mine just today finished the 211 mile hike on the John Muir trail at the Whitney Portal. He carried his DeLorme In Reach, and he and I were able to communicate throughout his entire trek. I was able to get him weather, look up routes for climbing peaks that interested him, etc. It was actually pretty impressive.
Just thought I'd throw that out there for y'all.