I have two Garmin 550T units that have a color screen, come pre-loaded with all the maps, and have GMRS radio and camera. A great feature is that when I click on the key, it sends my location to my partner, and to Panty-6 at base camp. When they reply, it shows their location on my screen.
The only feature not on this, but available as an option is road following. Every route is direct line, rather than staying on the roads.
I also downloaded "Topo Maps" An iPhone app from Phillip Endecott. Because the iPhone is not cell dependent, the maps are usable with only Satellite signal. I also have a mophie phone case which effectively gives me 2 1/2 times the battery life. Once paid for (I think it was either 9 bucks or 13) ALL map downloads are FREE. As many as you want. Up to your phone's limit of capacity.
This summer we chased a cross-country Hang Glider pilot, who landed once in the center of the Sheldon NWR, and once out in the desert north east of Hart Mountain. He had just bought a NUVI, by Garmin (I don't know the model). It found and plotted routes on roads that were mere tracks out there. WE were on roads that hadn't been driven on in at least 7 years (my guess, and after checking with BLM who work the area). The Nuvi plotted routes from either Lat/Long, or Degrees, Min's, Sec's, and took us by road directly to the pilot. I was impressed.
Addenda, I had a Tom tom for highway. It sucked big green DD.
