Really good stuff and well worth its current 50-60 € price tag.
As a sidenote: to describe Hazelburn as "unpeated" is nonsense; in my experience, it is usually about as smoky as Highland Park.
Overripe fruit (tangerine?), leathery / farmy peat smoke, a softly vinous aspect (as if some ex-wine casks had been involved), caramel sweetness, grape juice, and a savory side. The addition of water coaxes out beautiful mineral and earthy notes: wet limestone and petrichor.
Pretty amazing stuff for a 12-year-old.
Also more full and rich than you would have any right to expect, though it kind of thins out toward the end. Peat smoke paired with the industrial / dirty aspects typically encountered in Springbank (duh) and Ben Nevis. Coal, ash, heating oil. Yet it's also quite sweet and fruity (strawberries and peaches, perhaps), which may be down to the cask selection, seeing as Springbank usually produces more tart fare. Perfectly fine without water, but a few drops don't go amiss, bringing out more oils and herbs. Crazy that this still seems to have substantial reserves even though it's already "watered down". I'm seriously impressed.
Due to the phenols, this one of course holds on for longer than an average unpeated 12-year-old. Nicely herbal, with camphor, eukalyptus, and ... rosemary? (Or I may be imagining things.) The leather persists as well, and I also get some intermittent flashes of winey fruits and tannins. Normally, I'd rate this kind of finish a bit lower, but I'd like the overall score to be a much-deserved 88, so what the freaking hell.