I have mixed feelings with my PN-20. Even though the Delorme does not have the SiRF, it is absolutely amazing when it comes to reception, and accuracy. With Wass enabled, I searched for a geocache and It brought me within literally 1 foot of the hidden cache. Coverage is great, with no loss of signal under heavy foliage.The unit is very lightweight, easy to hold and the button layout is good. The screen is very bright. Most of the time I get WASS, INDOORS!
It is true that you can download SAT-10 photography, 3DTQ (USGS),DOQQ (B&W MAP PHOTOS) maps, but the processor they used should have been much faster. With all large detail that these maps can hold, The processor is on the slow side when it comes to redrawing maps. Draw times are ok if you are walking, but if you are driving and using any of the photo maps, it's slow to redraw. I would not advise you to use this as a navagtion tool for driving, unless you have already created a route. Draw times for loading photo maps would be too slow, and at FWY speeds the gps will not keep up well. Then again, whos going to purchase photo maps for an entire trip right? You can simply use the topo 6 maps, wich are just fine for that sort of thing. Another cool this is that you can hook it up to your laptop, and have the laptop be your screen while driving. Thats very cool because you no longer have to try and stare at the small screen. In the settings menu there are a few things that you can do to help improve the processor speed. Battery life is great using the Li-Ion battery. The menus are highly customizable, so you can show whatever pages you want, in what order, and select what info you want to see within each map.
The PN-20 is the only GPS out there that comes with software ( Topo 6.0) With all other brands you are forced to purchase the software, which is usually around $100. Delorme's topo maps are considered superior to all others. When you purchase a new PN-20, you get $100 of free photo maps downloads, which is a nice touch. Delorme now offers high res color satalite maps, but if you plan on downloading an entire gmu, you will be spending a small fortune. All in all, I'm happy with it, despite the processor speed.
P.S. Delorme offers several states that show all the GMU's. Very handy!