Thanks, Sam! Informative stuff. I appreciate the link.
One of the things about GPS, is that you truly get a sense of how much time a mistake in the circle can cost you. At the time, you're thinking to yourself, I just hooked it a bit, or I just checked out one wrong boulder. Ignore it, move on, don't think too much. But you watch the GPS, and the next guy's dot has already nearly caught up thanks to that! Things to avoid.