I've never had the pleasure of trying an Oregon or a DeLorme PN-40, and I'm sure they are both very capable units. However, if you don't need the extra features these units offer, and just want a basic unit that will point the way to a cache, and includes the ability to easily upload from a PC, get something like the Garmin eTrex Venture HC. It has USB, a high sensitivity receiver, is small, rugged, uses AA batteries, and is relatively inexpensive.
The Garmin GPSMap 60CSX would be my recommendation. Its a great unit