We are new to Geocaching and wish to purchase a GPS. I am wondering what is the easiest unit to use and the most user friendly, with the best performance. We want to spend time caching...not becoming frustrated with a new unit that is difficult to use. The Delorme PN-40 sound interesting but I understand it has a steep learning curve. The Colorado seems like a good unit but my understanding is you have to buy a good share of extras if you want to play, such as maps. Can anyone explain these issues to us? Thanks for any help.