Tom,

I've had a 400 for about 18 months and it has worked well for me. Battery life seems good (I do use lithium batteries). The software is a little funky but I've been able to upload topo maps without much trouble. You do have to tell it which maps to use. At least I haven't figured out a way to make it recognize which map to use based on its current location.

The only thing I haven't figured out is how to erase old waypoint data but then I haven't read the manual 3 time either yet.

If you buy any 3rd party software be sure it is compatible with the Magellan product line, not everything is. Have any specific questions PM me, I'll be glad to try to help.