Edit: I plan to actually do a blind taste test to put this question to bed and satisfy my curiosity. If anybody wants to beat me to it, please feel free.
If you make a salsa (for example) and store it in the fridge the flavors will marry over time.
Is the same true of compound butter? My hypothesis is that a compound butter that includes multiple flavoring agents (perhaps two different herbs) will taste essentially the same right after it has been compounded as it will after an overnight banishment to the refrigerator.
My initial reaction is that the magic that is helping salsa ingredients mingle is water (a solvent extraordinaire & excellently thin transport medium). Will butter insulate this wonderful exchange?
This Alton Brown recipe (http://www.foodnetwork.com/recipes/alton-brown/compound-butter-recipe/index.html) suggests chilling for two hours before serving. He's one smart cookie, so I tend to follow his lead, but is it worth waiting?
Image from another recipe here: http://www.thehungrymouse.com/2009/03/27/fresh-herb-compound-butter/