we also use the delorme product with the USB gps antenna. Pound for pound it makes more sense for us to have a multiple use device in the laptop, and we feel that the auto route feature has saved us a couple of times (Grass fire across I5 in OR, 2004) and a building fire across the road enroute Grand Canyon where we were routed through the neighborhood, while traffic sat for 2 hours.
we fueled on the other side and rolled on! BTW has anyone found any "Easter Eggs" on the Maps? seems some of the cartographers will add a detail here and there, but usually in remote areas.