I think this whisky is underrated. Yes, it's true that the nose isn't spectacular but it isn't as thin as many reviewers say in the mouth.
I drank a glass from a new bottle, so it took about 25 minutes to open up. Very nice once it did.
Nose: Linseed oil, pine, salted caramel, vanilla, a bit of alcohol mustiness.
Palate: buttered toast, malt, smoke, salt, Meier lemon, butter brickle, popcorn, flax, vanilla cake icing.
Finish: Medium. vanilla extract, clover honey, toasted barley, and a touch of oak. Does not end as dry as I had expected from reading reviews. Neither does it end bitter. A nice, sweet finish, but not a "sherry" finish. I must say, that sherry is overdone these days in a lot of whiskies. It's not everything it's cracked up to be. Drinkers in the 1970's understood that.
In my estimation, at 40% this scotch does not require any water added to it, especially if one has the patience to wait 20 minutes before getting into it in the glass.
I suspect the sherry fad will fade a little with time when people rediscover the joys of a whisky that doesn't need to do backflips on your tongue in terms of complexity to qualify as a truly delightful taste experience. Sometimes simpler is indeed better, depending upon one's mood. And for this, HP 15 should be waiting in the cabinet--a willing accomplice. Yes, I know there may be some sherry casks involved in making the 15, but they really don't stand out. In fact, I would be interested to learn if bourbon American casks were used, or European oak (sherry) casks. That would be interesting to know. I suspect European, but the sherry is really dialed down nicely.
The mouth feel after thirty minutes was really quite nice. I would rank the satisfaction index even higher than the rating. It's true that this HP isn't as complex as the 18, but it is quite delicious.
I also don't care what other reviewers say: the 15 is certainly a more interesting whisky than the 12. Call me a purist, but I like the fact that the 15 does not have fake coloring in it. But what's more, it is more exotic and interesting as a whisky than the 12, which has a stale mundane quality in comparison with the crisp, refreshing almost turpentine tang of the 15, mixed with a really satisfying sweet finish. Drinking it reminded me of my days painting with oils in college. I really miss painting and drinking this whisky gives me some of that nostalgia of the sharp tangy smell of oil on the canvas with linseed oil (turpentine) nearby to clean brushes and things.