Wonderful, wonderful stuff. A Puerto Rican rum you can enjoy straight, as opposed to most rums which can be drunk straight but burn like the fires of hell on the way down.
Añejo is "an ancient Castillian word meaning 'aged'", (so says the bottle) and that's exactly whay Bacardi Añejo is - a blend of Bacardi rums aged for up to six years in oak barrells. The rum loses its harshness and gains the flavour of oak, making it taste like an aged whiskey (for instance Gibson's Finest) but with greater sweetness. Do not mix this rum with Coke as that is a disservice to the rum. Enjoy it neat (that means straight) or with ice. Oh yes, and Bacardi Añejo is only a bit more expensive than regular rum, (i.e. I can get a bottle of Bacardi Carta Blanca for 17$ and the Añejo for about 23$ (those are Canadian dollars though, so YMMV) ).
Bacardi Añejo also recieves a shout-out in Hunter S. Thompson's Fear and Loathing in Las Vegas when Raoul Duke orders up a bottle, with ice, in preparation for a night of introspection and writing.