I just recently purchased a Magellan Triton 400 (the adventure package with the National Geographic Topo! Explorer Deluxe mapping software). I really like the GPS. Excellent sat aquisition and holds it's signal. The problem is the freakin mapping software that it came with. It was a bear to figure out. And now I just found out that you cannot purchase any more points to download the 24K quad maps! The vantage point software that it came with says the unit is past expiration date to subribe to it. Unbelievable!!!! So, I am looking at topo USA for mapping saftware with this unit. has anyone had any good experiences with topo USA? Im not trying to get into another bear of a learning curve here.