I live in Maryland, USA. My Dec bought One XL does not show several of the streets in my area. These streets are fairly new, 2 - 3 years old. I am tempted to upgrade my map with the latest version. My question to the forum is, what is the difference between upgrading the USA-Guam map, or simply buying the US Mid Atlantic map, which where I live and will do must of my driving? Is the map much higher resolution than the USA-Guam map? What is the advantage of buying the section/region map vs the whole country?