Tried four beers at Collins, Abyss Imperial Stout, Stone Old Guardian 2005, Left Hand Brewing Oak Aged Widdershins, and the Naked City Hoptrocity Rye IPA. The Stone Old Guardian was very impressive for a beer nearing 3 years old. Still retained excellent hop character. Brewtopia's Hoptrocity was excellent as well.
Afterward we headed up the hill to Naked City Brewing Company's corporate headquartes (AKA Brewtopia's Condo) where I sampled his Saison, some more Rye IPA, and the Berliner Weisse. More excellent beers that will be sucessful on a commercial scale.
I finished the night up at Elysian Brewing Company, at their winter beer festival. By that point my tasting skill had been dulled by too many good beers, so I can't really say which beers stood out with the exception of the Great Divide Hibernation Ale.
I would say that the opportunity to taste aged beers, not readily available to the consumer is one of the benefits of these type of events. While I have read quite a bit about beer aging, I have had limited opportunity to see what mature beers can become.