My problem in heroics has never been DPS, it's been ohshitIforgottohealthetank or whatthellhowdidthatshamandie? Or bosses that are just ridiculous in dps that straight up healing and no dps will last through (I'm looking at you VH bosses) or guantlet style shit where one mess up means death (CoS, first boss in AN, Skadi). Really dps is no big deal, I might take a little longer to kill a boss, but its never been "shit if only I had more dps that boss would have died."

edit: however I find it really sad how bad our dps is compared to the darlings of WoW (boomkins, mages, hunters) and I am glad they are at least doing something.