Personally don't do any real cellaring, but some friends do. Had this passed on and shared with some coworkers Sunday.
2006, we think. Properly cellared. First ever Julios Liquors/Berkshire Brewing collaboration. Berkshire Scotch Ale (which is solid) aged in a bunch of Buffalo Trace (I think?) single barrels Julios had picked. Including a Pappy 15 single barrel (this specific one I'm sure of). Yep, back in 2006, before #newmoney, Pappy single barrels could be aquired without too much fuss.
Apparently back then, this was in the top 10 on BA for a good while.
And it held up STUNNINGLY well for a 9+ year old beer. We were expecting kinda interesting "for science", but got an outright superb beer. I don't recall if I had it fresh, so no good comparison. On the thin side, but far from distractingly so. Lots of wood on a mild, leathery body. Loads of oaky bits and sharp tannins. Strong, clean whiskey notes. Not boozy, but nicely warming.
My buddy thinks he may have as much as a case left...