I used SPOT on a recent motorcycle trip to from Seattle to Copper Canyon Mexico, 2500 miles each way with my brother.
I loved it, or more accurately, my wife loved it which makes me quite happy.
The device was $149 + base service for a year + optional tracking for a year + evac insurance for a year. It worked out to roughly $300.
We didn't intend to use it as an emergency location device and the Help me function was useless in our eyes since our family was so far away. We used it to touch base with family when we knew we were out of cell phone range. It worked like a champ.
Enclosed are screen shots from what my family could see.
I would use it in both passive tracking mode (Track) as well as OK mode(ok).
OK mode takes a manual push on the device and my wife knew I was pushing a button to specific I was ok. There is drill down on each message.
It can be overlay on their maps with a push of a e-button.
Once, it fell from my bike at 40mph or so. It doesn't show a scratch and continued to perform without a problem. I consider it quite robust:-)
I kept it in my clear window folder on the top of my tankbag. This worked well although I assume that I blocked the required line of sight occasionally with my body. In either case enough messages went through to give my wife a level of comfort.
I don't think I would use it as a EPIRB or an emergency device because the reliability wasn't there for a true emergency.
That said, it was great for me to send a comforting message to my family that all was ok in an area where cell phone coverage was either expensive or unavailable.