Hi Sparks: No question is too dumb on this forum and all are worthy of an answer so continue to ask away!
I have had great luck with AT&T in both areas. But be aware, there are pockets of non reception in both. Some can be for a longer period of time or just transient so be patient. It really depends on the location. I'm sure this holds for Verizon as well. For instance, I usually have no problem with AT&T, but at one of my inns, I have no reception inside and have to stand outside at the horse corral to talk to anyone! I can also lean my head out my room window at the inn to get any reception but that can be cold!
When traveling with friends, one can have reception on Verizon and none on AT&T and vice versa.
Not sure about the GPS coordinates so anyone else can help with the question I'm sure.