I will vote for the 16th at Old Mac because of green at Old Mac is better than the small green at St. Endoc. I have played Old Mac but can only judge St. Endoc from photos and other commentary.
I also think Old Mac is a better hole because of the bunkers front and right. The one thing I do like about St. Endoc is the bunker in the dune which adds a little intimidation but really does not add anything to the value of the hole.
This is kind of liking picking teams to advance in the NCAA tournament. Lots of good holes with a few flaws. We each like holes or teams for different reasons.