If we are talking ASL, I thoroughly enjoy a 68" and even a 69" bow, especially while roving/stumping.
As I transitioned from recurves and duo-flex style bows to the ASL around 2005, within a year I found my draw length quickly changed from 31.5" to a solid and repeating 27". Those in the "know" told me that, for the ASL, my optimal bow length is 66"
So....that is where I have been hangin'... but looking to add a 68" to the mix in a few months.
As Charlie pointed out and in practical hunting experience over the past few years the difference between these bows equates to a whopping 1" at either end....no biggie!