BST is not a DD really, but you can do a lot with it. BST was the first job I leveled... once you've got it set up decently you can do a ton. For some older content people will want you along. For some strategies for newer content people will want you along.
BST is good at
-exp
-farming dynamis
-Walk of Echoes (a not very popular endgame event that has some pretty decent drops)
-soloing random stuff
-most level 75 era content
BST is not in demand for:
-most organized abyssea megaboss/seal/Key Item farming (though can solo a lot of seals)
-Voidwatch
-Neo Nyzul
-Legion
(Edit: not 100% sure about legion but it strikes me as something we would be fairly useless in)
Edited, Dec 3rd 2012 10:21am by Olorinus