The Bourbon Society recently picked a single barrel of Buffalo Trace bourbon. There are people who immediately wrote it off as a "Vanity Label" because it was not barrel proof and unfiltered. I immediately lose respect for these people and this bottling of Buffalo Trace supports my position. This is not simply a Buffalo Trace with a "vanity" label on it. The bourbon is very different from regular Buffalo Trace with rich apple fruit and spice that reminds me of apple butter. A bourbon does not have to be barrel proof and unfiltered to be special. It can be quite good at bottle proof and filtered. In fact some bourbons over 12 years old can benefit from filtering and those over 15 years old should be filtered to get rid of excess tannins. As far as high proof is concerned, if the bourbon is over 110 proof then you are pretty much killing your taste buds with the first drink so you should add water if you want to enjoy tasting the bourbon over time. There is nothing wrong with lower proof bourbons. They have their niche to fill as well as the higher proof bourbons.
A single barrel selection program can be more than a vanity bottle if the tasters make it so. Insist upon a barrel that does not meet the normal taste profile and you will have a unique bottling of bourbon.