A while back, I saw some science about these vs a humongous lump of ice, and ice won. This isn't the same article, but it sort of explains it:
There’s something about Holiday Gift Guides, in magazines and such, that I find tremendously frustrating. Not because the suggestions are worthless, but because every single one seems to be j…
drinksanddrinking.com
The Cardhu is so smooth, it doesn't need chillng, but if I was to be drinking something like Glenfarclas 105 or a standard blend like grouse, or even an Islay, I think I'd stick a small moon
(That's no moon...) of ice to cool the burn or to help release some of the complexity.