Caol Ila/Mortlach. Advice needed

Cask Strength, and also a MMD Mortlach 1990; could someone maybe tell me something about theese?

I have a Dun Bheagan Caol Isla (distilled 1990 bottled 2000) at 43% and it is terrific. My Murray McDavid Mortlach (should be about the same vintage but I can't dig it out just now), is, I find, over-sherried to the point that the subtle fruit and smoke of Mortlach are almost completely lost.