Can't argue with what you said too much... personally I haven't experienced my dps or any spriest dps in the raid as being a drawback. Admitadly our guild performed poorly for the Uld teir of content and we didn't see as many hard modes as we probably should.
I would say that spriests are highly dependant on raid buffs, much more so than any other class i've played. Just for example my spriest will do around 3.5K solo dps on a target dummy, yet my very poorly geared feral druid can do 3K... and when I say poorly geared I mean using tanking items as dps items for several slots and still in blues or Naxx10 epics... my spriest is pretty much in the best gear I had access to which was the first 3 hard modes of Uld and all hard mode Uld10 (except Algalon).