All in all two very fine Bladnoch with different profiles. Very interesting to see how the distillery character changed over just one decade. But this was the decade with the most changes to the production processes in all Scottish distilleries (switching from direct firing to steam coils, abandoning own floor maltings and more).
Both are golden with the 1966 maybe two shades darker than the Rare Malt. The 1966 offers a rich, almost bold nose on fruity and floral aromas together with a nice honey driven sweetness, very complex and balanced. Due to its high abv of 53.6% the 1977 needs some time of breathing before releasing a more winey and slightly cheesy profile. With water it opens up further, of course and shows more aromas of a sweet wine. This round clearly goes to the older vintage.
The 1966 vintage has a very complex yet well balanced profile of barley sugary, slightly woody and floral/grassy flavours. The Rare Malt is more on the fruity (oranges, lime) and herbal side imbedded in a sound sweet and wooden structure. With water it gets smoother but a little thinner too Hard to judge on this, but I see a slight advantage for the 1966 again (due to its greater complexity).
Bold and instantly mouth-coating with the 1966 - fat, oily and coating too with the 1977. Both are very good at the first sip and I vote for a draw. Both own a very long finish with the 1966 slightly drying out at the very end, but not too unpleasantly. The 1977 got some peppery moments here but no drying at all. Water is not needed. This time the Rare Malt wins.