It is funny that two of my all time favorite golf courses have out an in routings with a loop at the end. Obviously I am talking about Deal and St. Andrews. For the locals down in Kent who get to play Sandwich, Rye, Littlestone and Deal, the criticism I often hear about my beloved Cinque Ports is about the routing. Out and back is simple, it is mundane, you get parallel holes etc, the wind direction is basically the same (it isnt, there are various different tacks to the wind, often subtle b/c the holes don't go out exactly at the same longitude)
Meanwhile, cheek by jowl from Deal is Sandwich which has an almost circular like routing, akin to Muirfield or Shinnecock. Here you face a different wind, a different test and some may feel a superior challenge. I can't disagree with this. But to me something about the ol' out and in is endearing. Perhaps it the becalming feeling of knowing what lies ahead and being able to mark the journey a bit easier..
So for me I can't say I'd always favor a circular routing vs. out and in but I'm curious to see if anyone else has thought about this..