Frank it does look interesting and would certainly help family etc track your wanderings if that is what you wanted.
If I was hunting or traveling in the wilderness by car a lot, it would be a great idea. I have been up some logging roads for 25 and 30 miles and it would be comforting to be able to signal someone if there was a problem of some sort if the truck got stuck.
In my case I have opted for a 406 mhtz GPS driven personal locating device that also has 121.5 signal output. That is on top of the 406/121.5 ELT in the aircraft. The reason being it is registered and it sends out a signal that is monitored continuously and that S&R will respond to it quite quickly.
With 406, I think they get you almost immediately and with the GPS providing lat/long, you can be found pretty quickly if you activated it.
My opinion would be that SPOT looks great, but a 406 with GPS might well be the better option as a pilot. Having flown in Northern Quebec, the Artic and other places, I would not want to have to wait for a family member to get around to checking where I was before raising an alarm.
Another way of looking at it might be, I have OnStar in my truck, but would it work in my plane? Let me think about that.
Besides, if you badly needed a beer and a Hooters was the only game around, would you really want everyone to know?
Blue skies - Dave