Do you really have to buy the maps for it? Check out the reviews on the Earthmate PN-20s here is a post for you to look at..
www.delorme.com//about/reviews/PN20_GPSReview.htm
Also something that is new to the line of Earthmates.. the PN-40 here a press release on them..
www.delorme.com//about/pressreleases/PN-40.htm
Also the PN-20 is being used for the 2009 North Pole expidition.. Theremust besomething about the Earthmate.. You can read about it foryour self here..
www.delorme.com//about/pressreleases/NorthPole09Sponsor.htm