Never owned one, know little about them. Wanting to buy one, and been looking at, searching for info. I see some are mapping, and non-mapping. Little confused on this, and all I can gather thus far is it means when gps is tracking your movements it won't be displayed on a map background. Now does this mean you cannot load any topo maps at all into the Gps unit? Also does this mean you won't be able to download your movements onto a computer map?.