I've had a PN40 for just a tidge under a year now. To cut to the chase, I'm pretty happy with it, and I would recommend it.
Now, this is the first GPS unit I've ever owned; so, I have no experience with Garmins for a comparison. I bought the DeLorme because I've always been impressed with those red state road atlases they publish. The PN40 came with a topographical program (Topo7) that seems to be a rendering of said DeLorme atlases on the display screen. With Topo7, I can tap into DeLorme's web site and download aerial photos, nautical maps, or USGS topographical maps that will show up on the screen in lieu of the Topo7 map. You store the DeLorme maps and downloaded maps on a standard SD card. For $30 a year, you get infinitely many downloads.
Power supply is 2 AA cells. It comes with a rechargable battery that will last about 3 hours with the screen light cranked up to maximum and always on. I find the screen hard to read if I dial down the luminosity.
I use it mainly for geocaching, and it always seems to get me pretty close to target. Caches that I haven't found are probably more from my spotting skills rather than the PN40.
A feature that I like is that it will leave a breadcrumbs track so that you can retrace your steps without having to note landmarks while hiking.
Potential drawback: It's very menu driven, with a lot of drop-downs, some of which are obvious, and some not. I always pack the user's manual with me on a trip; if I want to do something tricky, I'll invariably have to refer to it.
Another drawback is that the control buttons are small. I was out snowshoeing yesterday in that snowstorm in northwest Michigan. I had on medium weight gloves, and the unit was really hard to operate. Would have been impossible with heavy ski-type gloves.
So, that's a quick hip shot on my DeLorme. If you have any more questions, ask away, and I'll do my best to answer 'em.
