Penderyn is one of my favorites because it is the only young whisky I find truly enjoyable. It benefits from the prestigious 92 proof, a unique distillation process, and VERY good sources of American oak casks-- that being Heaven Hill and Jack Daniel. Their Madeira finishing adds some delightful notes of toffee and bitter orange zest.
My most recent tasting of Penderyn yielded a slight shift in character. I detected a very slight, olive-like briny taste, like that of Oban 14-year and some of the other Coastal Highland Scotch Malt Whiskies.