I like being able to bring up a USGS topo on my PC, zoom to where I want, mark a point, then download those points to my GPS.
I can print a map including my points if I want.

After a hunt I'll upload points collected in the field from the GPS to my PC database.

Over time that database of landmarks, kills, sightings, has become the most valuable component.

I keep a hard file of USGS, BLM, Nat'l Forest, in camp - mostly for the bennefit of the others in camp.

One more odd thing that has been helpfull. I post a plastic 3D relief map on the wall of my RV. Nothing else really compares to having a small scale model of the terrain.