Cuban · Brugal
Brugal is Dominican, made from molasses and aged in ex-bourbon casks, then filtered. It is drier than most aged rum because the Dominican style does not add sugar back afterwards.

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The one thing that matters
An aged mojito is a different animal. You lose some of the bright, summery lift and gain vanilla and oak underneath. Use a little less sugar, because the barrel has already done some of that work.
Yes. It is less traditional and less bright, but the vanilla and oak give the drink weight. Use a touch less sugar since the barrel has already added sweetness.
Many producers add sugar back after ageing. The Dominican style generally does not, so what you taste is the barrel rather than added sweetness.