From the bottle: Sweet and mellow. Malt, apples, caramel, honey, herbal, vanilla, ex-bourbon cask influence.
Neat, in the glass: Heavy malt with overpowering ABV that shuts off most other notes. This is probably not designed to be nosed neat.
With water (a few drops): Doesn't open up much, in fact it barely changes at all. This clearly needs a lot more.
With a spoonful of water (per dram): Now this is more like it. Pleasantly malty, apple cider, a nice dose of caramel and honey, some herbal notes, along with vanilla, with faint cask. Well balanced. Smells like a cross between a Glenfiddich and a Macallan, so yes it's basically Speyside meets Highland. I like it.
Neat: Malt and ABV overpowers everything. It's also on the sour side. This is definitely not designed to be tasted neat.
With water (a few drops): Just like the nose, this doesn't help much. We need to go deeper...
With a spoonful of water (per dram): Bingo. Now this is a proper whisky. Initially on the fruity (apple cider) and sweet side (caramel, honey, vanilla), gradually shifting to green tea and other herbs. Once again, it's like a cross between Glenfiddich and Macallan. It's not anything special, but it's still a decent dram.
Neat: Once again, this is clearly not designed for neat consumption. The finish is sour and even a bit bitter. Get the water in here ASAP.
With water (a few drops): See above!
With a spoonful of water (per dram): Even like this, the finish is somewhat short and lacking. It's still a nice cross between Speyside and Highland, but it's simply so thin that it's barely there at all. The ex-bourbon oak influence is somehow very mild. Where did the 11 years go? This is totally not what you expect from cask strength.
Final thoughts: all things considered, this is really more of a DIY kit than a standalone single malt whisky. It should therefore be approached accordingly. If you're looking to experiment with cask strength then yes, it's worth it. Otherwise, you might want to stick with proper malts out of the bottle.