The Baja GPS series (current is the 540C model) utilizes the Lowrance 24,000:1 Topo maps...which are the same scale as the NG Topo maps. However I have not seen them personally to see if the detail for map features (roads, trails, springs, etc.) is similar to NG. I know the DeLorme Topo maps I have (electronic and paper) do not show as much feature detail as my NG or even the Benchmark paper Topo maps. For where I go I need this detail...I'll probably just buy one of the Baja 540C's and try it out...then I'll know. They are shock proof I have been told and specifically made for 4x4 use...and since they don't utilize touch-screen technology they are #1 less expensive and #2 immune to scratched screen from use in thick dusty environments (like Nevada

). My only nit with the Baja has to do with saving a track...it apparently saves it on its internal memory as the track accumulates. But if you want that track on the SD card you need to 'move' if from the internal memory to the SD card...not a biggy but an extra step if you want to get the track onto a PC/laptop...