Have used my Spot II Satellite GPS Messenger http://www.findmespot.com/en/index.php?cid=102 for a couple of years. Have run through western US Wyoming and Montana, around Lake Superior, up to Alaska and as far north as Inuvik 30k from the Arctic Ocean and never had an issue. Had tracking running all the time and it worked flawlessly. Wife could look at the map and see exactly where i was and using street view see exactly what I was seeing. (not sure if that is a feature you want)Reading many, many reviews of SPOT, and I'm reluctant to purchase, given the quite large number of negative reviews. If a spouse thought you had a functional tracking device, and yet it failed to work...guess what: The spouse would assume something bad happened, which might be worse than no tracking data at all.
Still researching and soliciting comments from SPOT owners. Thanks!
Only minor issue is the need to use 3 expensive AAA lithium batteries but on our 25 day Alaska trip I started with the same batteries I used on our Montana trip last year and only had to change batteries 2 times.