Pretty much the quintessence of a successfully sherried Scotch. The buttery, floral, and fruity Glenfiddich backbone is still palpable, but it's playing second fiddle to the main attraction, which is an immaculate, old-timey, complex, and elegant ex-sherry-cask aroma. Nutty, velvety, dark-fruity and incredibly rich with buckets of umami aromas, this is a heavenly nose, particularly at this price point (ca. 35 €). Amazing value for money.
The taste fulfills the promises of the nose, and really, what more do you want? It's sweet (owing to the Glenfiddich Speyside profile) and simultaneously dry (owing to what I presume to have been mainly ex-European-oak Sherry butts), it's rich and unctuous, and it has a great three-stage development that oscillates between sour-fruity, nutty-sweet and tannic-tart. Love it all the way.
The finish is medium in length but beautifully measured, with nutty notes, cocoa and coffee powder, slight citrus, and some late vanilla.
Warning: Loses a lot of its luster when the filling level is way down, so finish it swiftly if you're nearing the end!