I've had this blended many times, but this review comes from one particular evening with my uncle, back in March 2015, at the terrace of a venue named Club Gourmet Callao (where they poured the dram on top of a huge pile of ice cubes for God knows what reason and I had to take most off. Besides, they used a G'n'T glass rather than a glencairn or an old-fashioned. Terrible.)
The scotch pours a rather dark shade of amber, verging on brown, and it delivers mostly peaty aromas; some water develop them even more: leather, bog, char... There's also a back hint of raw cereal. Mouthfeel is not very complex (even more: I'd say it's quite simple); smooth and slightly over-bitter. Finish delivers some smoky tones and a tinge of butterscotch, but it doesn't linger very long after sipping.
I'm inclined to think of this as an enhanced version of the Red Label: despite its being clearly superior (I'm not a fan of the Red), it's still produced as a mixer, not as a dram to be enjoyed on its own. It's a different story with the Double Black, even though the similar name might be misleading.