Do not under any circumstances buy a SPOT unit! It is unreliable in a 911 situation, and customer service is the worst I have ever experience.
Here is my story. I bought the unit for $200, and paid the $200 annual fee. I figured that if I ever needed it, the 911 feature could get me out of deep trouble, so it was worth the cost.
I went car camping with my 4 little kids, ages 10, 8, 6 and 4. While I was on the trip, the unit sent out a 911 message due to a malfunction. The good news was that I really wasn't in danger.
Here is the bad news: When the SPOT unit sends a 911 message, it does not actually go to 911. It goes to some call center in Houston. There, some dude gets the message and has to figure out what to do with it. From there, it is all down hill.
In this case, the dude called my wife and told her my unit had sent an urgent 911 message, and were we OK? and did she know where we were? Of course, she freaked out, thinking the kids and I were dead somewhere. She had no idea where we were and whether or not we were OK, and SPOT completely fumbled. The SPOT guy was completely clueless about what to do next. He acted like he had never gotten a 911 message before.
The SPOT guy then called my business partner and asked him were we OK? and did he know where we were? Now, the SPOT unit is supposed to tell SPOT where you are, right? The SPOT guy's computer wasn't working properly that day, or he couldn't figure out how to zoom in and out, so he could not tell...