Hey dperry: I have topo USA 4.0 and Mapsource topo latest version. I use these in conjunction with a Garmin etrex Vista GPS. They both work great although the topo detail is not as good as USGS data. They do tend to have a lot of roads and trails that are not on most maps. With the delorme there are some free down loads you can get. I got the USGS overlay for my hunting land and The satellite image as well. The delorme also does a great job with area calculations. I use this feature for timber cruising and soil mapping, but it would also be good for calculating food plot area.