I was doing a bunch of biathlon when skating technique hit the scene in the early 80s. It was hard to imagine using it for a whole race at the time, as it seemed so tiring and slow on the uphills. Once we started training for it, got the balance down and learned how to conserve momentum better, we were often frustrated by the difficulty of finding trails that were adequately groomed. When you achieve/find both it is like an entirely different sport.
The balance to ride a really skinny ski as far as possible on each foot is not something that most folk pick up fast but time on roller blades and roller skiis sure helps. Unfortunately the trails have to be pretty good to allow you to take advantage of the momentum. Williams Lake used to do a great job with trails but have recently closed. Now I usually just go to the Van Hovenberg trails outside of Lake Placid for reliable snow and grooming.
I hear ya, Phlan, about a ridge tour, but also find that it about as fast to use snow shoes as to track uneven terrain in b/c skiis, unless you can really take it out on some big downhills.