DeLorme has been doing digital maps for a long time, and their expertise shows in the Earthmate PN-30 GPS unit (waterproof, baby!), sitting in the middle of the Earthmate lineup between the -20 and the -40 with a 32 channel chipset, dual core processor and 500MB of memory and only giving up the 3-axis electronic compass and barometric altimeter.
Setup of the lighweight 6oz unit is slightly confusing (what GPS isn't?), with little description of some of options (saving maps to SD card versus internal memory, the Topo USA 8.0 versus the PN map CDs) and a few other small glitches (when done transferring to internal memory it says done transferring to SD; refers to "the connect to computer page” but doesn’t say how to get to it).
The PN-30 took a while to get its first fix, but after that it was fairly snappy. It laid a nice track on a 15 mile through hike, but for some reason the backlight wouldn't turn off and by the end of the eight hour hike it was dead. A quick search of the DeLorme website yielded an easy fix, and since then battery life with two AAs has been good. More concerning was the screen locking up at one point, but since then I've been unable to replicate the problem although I found reference to it on user forums. The software is amazing, but takes some investigation to get a handle on. The 3-D views are very cool and you can generate any kind of data your skeevy little heart desires.
The unit itself is a bit thick, and for some reason the lanyard is at the top of the unit so as it hangs around your neck the screen is upside-down, but otherwise the PN-30 fits nicely in the hand and the buttons provide good usability. The screen is quite nice, rendering topos beautifully. Overall the PN-30 is one of the better GPS units we've seen. The problems are minor and mostly common to outdoor GPS units (confusing setup and map management), which in general have a ways to go to match the friendliness of, say, in-car units. The maps, once you figure the software out, are great fun. If you're looking for a rugged, waterproof GPS with powerful software the DeLorme Earthmate PN-30 fits the bill.