I had a glass of 2014 bottled Glendronach 18 OB next to this one, and blind I probably wouldn't say they are the same distillery.
Starting out with sherry and sal-ammoniac. This is fatty, rich, and thick as treacle. Artisan chocolates, armagnac meatiness, wet cigar leaves, dried cherries, chess pieces, and cigar ash. Some cloves (sulfur), OBE peppermint. Opulent, yet grotesque. Not at all civilized like the Grandeur series is now.
Deep and rich. The first sip really catches my taste buds. Sal-ammoniac, tons of dry licorice, Tastes old and well matured, with some bitterness that stays well in check. The heaviest licorice ever, really. Some herbal touches and a bit of peppermint, and some perfume. Quite heavy, with treacle and dark, unsweetened chocolate.
Lasts long, with licorice and sal-ammoniac and some rooty touches.