OK I am going to say this and I realize this is not the "norm" but it is my experience none the less.
I have had nothing but trouble with my spot when traveling abroad and have even thought of asking for my money back. I know my experience is contrary to pretty much every one else on expo but so far mine has been a real piece. I have had it give bad locations, no locations, and fail to check in SEVERAL times. Once the non functioning check in almost resulting in a S.A.R. call because I missed 3 consecutive check in's. The bad thing is you don't know if it's messing up untill you get home. My spot lights showed all three check in's sent with out problem but when I returned (and everyone calmed down bc they thought I was dead) I learned they in fact did not send. I have also sent several emails to spot (both in the US and while traveling internationally) and have never heard back to ANY of my emails. When I send the test check in's like the directions say it works (most of the time), when I travel anywhere outside of the US I am running about 20% of the time it works,in the US it averages about 50% of the time.
Overall I hate mine and wish I had never spent the money on it....