Last time we went to Candlelight Processional, there was a standby line. I honestly don't know how many in the standby line ever made it in to any of the shows, but the line was extremely long and from what I overheard, people were waiting for hours on end. From what I understand, the more popular the narrator, the longer that line will be. We have stood outside the theater to listen and see whatever we can see through the crowds and obstructions. Granted, that was before the dining packages really got popular. We also weren't the only people trying to do this...and CMs still had to keep passing foot traffic in the area flowing.
Personally, I would opt for a dining package if possible. It greatly reduces the stress of getting in, you have to eat anyway, and you're not spending the bulk of your day in a line that may or may not yield positive results.