With water things are more sweet on the nose - meaty, sweet bbq and I get more of the sherry sweetness now. Taste is much more tame - with a hint of chocolate... but still BBQ meats, sherry, and spice. The finish is now spicier, but with some sweet, hot pepper and still ash in the back.
The 50.9% is a nice touch on this, and it really is quite different with and without water - worth trying both ways. It cost $85 when I picked it up, and like most Ardbeg one offs I'll never see it again. It's different enough that if you're an Ardbeg fan and you see this at a reasonably price you should pick it up. It's not better than any of the core line offerings, just different. I'll rate it a 4.0/5.0... cheers!