As a DRG main, I'm definitely annoyed when a slow tank makes Blood of the Dragon fall off. That said, learning when you can pop cooldowns without being screwed for boss fights is what dungeon mastery is all about for me these days. On an average run I know that I can pop some stuff during each boss fight and again on the first trash pull after, and it'll come off cooldown just in time for the next boss - it just takes practice and planning ahead.
