I was just looking at a SPOT at Amazon and then read a few of the reviews. Some were quite positive. Some where quite scary. There are reviewers that say SPOT's response center was inept, others that say the device's performance is never consistent and it doesn't work through tree cover.

There are other reviews that say the people with problems haven't read the manual. One review states that say the unit must always be vertical. Another states that the unit must always be horizontal. Customer service at SPOT doesn't seem to fare well at all.

Worth reading if you are considering one.