I've been backpacking for several years and have always relied upon a traditional paper map and compass. Got a GPS unit with my REI dividend and didn't know what else to spend it on. Wanted one of the Garmin oregon units but they were out of my price range. Was a toss up between the DeLorme PN-40 and a Garmin eTrex Vista HCx based on customer reviews. I eventually went with the DeLorme. What sold me were the maps that are available. Both units got good reviews, but I wanted more bang for the buck in the map department. However, consider that the Garmin eTrex can get up to 25 hrs on a pair of batteries. I won't get even half that with the PN-40 on regular alkalines. Haven't tried lithiums yet. There are DeLorme forums that talk about ways to get more battery life out of the unit. I haven't checked those out, but I assume turning the screen brightness down and turning the altimeter off are options.

I've used the DeLorme for some Geocaching and a bunch of hiking. Has worked great for both. A complaint, though minor, is that it's been taking up to 2-3 minutes to get a satellite lock. Don't know if that's normal.

I may also look into solar battery chargers for long backpacking trips so I don't have to carry a ton of AAs. That being said, you'd always want to carry a paper map and compass.

It's easily viewed in sunlight as well. All in all, I'm happy with my PN-40. Hope this helps.