I have one of the original PN-20's that I got 3 or 4 years ago. Haven't ever regretted getting it. It's very easy to use and really intuitive. I haven't had to look at the manual since the first year I had it. When it came out it had the most options in the way of what kinds of maps and satellite images you could load on it. I haven't looked at other GPS's since then so I could be wrong about this, but I still think the DeLorme GPS's are the only ones that can load up the actual USGS maps. I really like being able to look at the screen and seeing exactly where I am on the same map I have in my hand. The satellite images are nice to have, especially when you are looking for an open area or clearcut. When I got mine, it came with $100 worth of downloads. I loaded up all the areas I wanted and still have a credit with them. The Delorme TOPO USA that came with the unit is a decent map for area's you don't want to download the USGS, but it isn't as detailed as the USGS.
My only complaints are: In the forest with heavy cloud cover, it can take a while to get a good signal. I imagine with the latest models, the reception is better. The battery indicator is not too accurate until it is ready to shut down due to low power. Also, the TOPO program from a couple of years ago is a not the easiest program to use but it gets the job done. Maybe they have improved it since I got mine.
The new PN-60 model with the SPOT Communicator looks nice. I do a fair amount of time in the backcountry and it would be great to have.