Ultimately, cellared Imperial stouts, and barrel aged stouts fall into different categories. I think a well aged Imperial wins over a barrel aged beer, simply because you get flavors and complexities missing from a barrel aged brew. I recent sampled the past few years of Brooklyn Black Chocolate stout. With the exception of one year which was sort of over oxidized and off a bit, the rest were amazing. It's hard to beat just plain old cellared stouts, Narwhal included. I just drank two that I in the keezer/cellar for the past couple years and they were pretty darn good. Of all the aged stouts I have had recently - my vertical of Dark Horse Plead the 5th has to be the winner. Plead the 5th is a pretty average stout in my opinion, but is ages better than anything I have saved.
In other news, now that I have drank all those verticals down, I have been able to clear out my fermentation chamber so that I could just possibly brew a batch of homebrew. I had wanted to brew a Black Tuesday clone two years ago before I left Michigan, so hopefully I will get my chance here soon.
One thing I would like to add - it is easy to forget that Narwhal is a product of Sierra Nevada one of the largest breweries in the U.S. They still make what I consider to be Craft Beer, they have not sold out, and their products have not went to hell. Not only that, they still can turn out a quality special product like BA Narwhal. This is no small feat. No other brewery I know of has maintained the size/quality ratio that SA has without selling out. Kudos to Sierra Nevada.