The biggest thing with Spot 2 is to make sure you leave it on for the 30 minutes or so the instructions tell you to when you are sending a message or checking in. You can't just turn it on, hit a button and turn it off. Just because the little "message sent" light lights up, doesn't mean its fully sent off yet.
Me in my genuis thought I'd save batteries the first year using it, and turned it off too quick. This resulted in conversations between my wife and SAR- and I had no idea she was worried- just happened to get up on a ridge where I had cell service and thought I'd give her a call.. wow she was soooo pissed and worried all at the same time!

If you go this route, set your man card down for a minute and read the instructions before you leave, and bring the little instruction book with you. Pack up an extra set up lithium AAA's in your first aid kit or something too.. mine went dead on me this year and I was glad to have the back ups ready.
Not sold on the tracking either, it sucks the batteries out pretty quick and is an extra expense.