In order to understand better this I'd like to explain how Google maps works.
When you create a map you don't have the option to choose the zoom level nor the map type (normal, satellite, hybrid or terrain).
Let me explain this with an example; I need to create a map of Australia where I have several customers in different cities, and I want to create a map with a zoom level of 18 with a map Satellite map type; Now I create a map of the U.K again with several customers location; so far so good. Sign out and come back later, click on my maps, check box the U.K map and it loads fine, now I uncheck the U.K. map and click the check box for the Australia map; not so good I don't see my Australia map nor my saved map points there. Instead I still see the U.K map. What's going on here; well Google maps is not saving the right location, the map type and zoom level.
If you do the same with pinmaps.net each map will be saved individualy with it's own zoom level, map type and so on. They will show to the user as a drop down box and each map point on a list box. Here again each map point will be saved with it's own zoom level and map type.
Go ahead and do your own testing to see what I mean.