Figured I'd provide a final update on this, even though I'm sure no one is interested. Just in case..

I did set the mooring several weeks ago and the boat has been living happily on it since. I can't over-state how helpful it was to have the range finder. Not only did using it drastically reduce the time it took me to locate a good spot and properly position myself, it enabled me to set the mooring in a good bit closer to shore (and thereby shorten my dinghy row to and from the boat each time) than I most likely otherwise would have, given the certainty of my positioning and swing radius. When you are talking about a 60' swing radius (30' of chain and 30' of boat, engine and distance between boat and ball), it was quite helpful to be able to be that precise. Also, to my eye, I was pretty far off in guessing distances. I look at a boat just over there and think 40-50'. Look through the range finder and it's 90', plenty of room!

I definitely plan to bring this with me on future trips and have no doubt that it will be helpful at least once or twice per trip when anchoring.

Anyway, hope this information is helpful to someone. Thanks again to everyone on here for the insight and advice!!