Well, I bought the Good Sam GPS and have to say I couldn't be more disappointed. It is probably the most user unfriendly electronic device I have owned. It follows a logic that was incomprehensible to me until I finally broke down and called there customer support. I still have trouble using it because I forget their logic between uses.
I thought the Hopkins Towing Solution TPMS I bought was ridiculously difficult to use but this GPS might be worse. I am probably going to throw them both in the trash. (Unless, despite what I just said, someone out there would like to buy them.)