UPDATE: Check out my hands-on DeLorme PN-40 review

I'm fortunate to have a DeLorme Earthmate PN-40 in for testing, and I thought I'd share some initial impressions since this unit is due to become available in the next week or two.

Like the PN-20, this new model lets you view your position on aerial imagery. But a number of upgrades promise to make this an even more popular handheld than the original:

• A dual-core processor makes map redraws and menu navigation very fast, and I can already attest to this; even at 60 MPH, map redraws were nearly instantaneous — I saw only brief flashes of blank areas on the screen
• Tri-axial compass (meaning there is no need to hold it dead level)
• Barometric altimeter
• SDHC high-capacity SD card support
• A more detailed base map

And hardware isn't the only improvement. The previous ala carte imagery plan is gone; an annual, all you can eat download $29.95 subscription plan now gets you aerial imagery, USGS topos and NOAA marine charts galore. It's an incredible deal.

Before we leave hardware entirely though, I should mention one downside — the diminutive display — 2.2", which is made up for somewhat by it being a relatively high-resolution (220 x 176 pixels) screen. The image below compares the Garmin Oregon (which has its own display issues), Garmin 60CSx and the DeLorme PN-40.

I'll have a full review posted ASAP. But with six review units in hand, it may be awhile! So in the interim, here's my initial take…

Barring any significant accuracy problems (which I haven't been able to test for yet), the PN-40 looks like a great backcountry GPS for anyone who wants to really dig into it. You can create your own trail maps, use aerial photos, overlay contour lines and do much more.

Having said that, don't expect it to be as easy to use as a Garmin. If you want this level of functionality, you're going to have to get your hands dirty; those aerial photos and USGS topo maps aren't pre-loaded — you have to add them to the unit via the included DeLorme Topo USA 7.0 software.

I've ribbed DeLorme in the past about how complex the software was, but this time I didn't find it nearly as hard to use, perhaps due to some new (?) context-sensitive help screens. Granted, all I've done so far is load maps to the unit, but with only a couple of minor stumbles, I got a full set of topo maps and aerial photos for my area loaded on the first try. Still, if you're a very casual user or if you struggle much with software, this may not be the best choice for you. That seems to be the big trade-off with this unit.

I'll close with a bevy of screen shots. A couple of caveats though — there is no high resolution color urban imagery available for where I'm located, so don't expect too much detail there. Also, the settings I used when collecting the screenshots switched to aerial imagery before bringing up the clearest USGS topo map imagery, so that is missing too. At the very bottom are two screenshots for those from DeLorme.

Screenshots below courtesy DeLorme: