This is one of my favourite distilleries for older bottlings - often super yummy with quite a bit of variation. I've had probably close to a dozen different family casks from the 1960s and 1970s and there is a pretty big range of taste between them.
You should have seen what they poured at "The Nth" in Las Vegas last weekend for GlenFarclas - let's see:
40 yo single cask
1966 single cask (I think different than the 40yo single cask above)
And, a 50yo family cask.
I only managed to get to two of them (the 40yo@46% which was awesome, and the 1966) but others managed to get all of them. Yup, it was a bit ridiculous and a good time was had by all!