Hi
I have had the great pleasure in tasting both the Rum & Sherryoak finish. I have to say that both of these Balvenies are exceptional, since tasting both I have bought 2 bottles of each for keepers - although tempted to open one of them soon

Yes I would recommend purchasing at least the Rum cask and then move onto the Sherryoak - once satisfied it might also be worth getting one for keeping as the Sherryoak at least will be gone from the shelves for good this year
Slainte The highlander