I've got a Garmin E-Trex, no downloadable maps, but you can set it to map your travelled routes, for example, roads around the area, and then use them as reference points etc. The new one I got has a high sensitivity receiver which works extremely well in some of the thickest rainforest I've ever seen! It sets way-points to make your way back to a chosen location...
As a budget buy, I was very happy with the toy overall!