I agree with this last sentence. Not the rest. Ask the Eagles about McNabb or the Colts about Manning or the Chiefs about Ryan Simms or the Bills about Mike Williams. You can ask any number of teams about any number of positions that were busts. QB's aren't that much different than other positions in that sense that 1st rounders are more likely to be successful, though there are lots of exceptions.
Personally I wasn't a fan of the Whitner pick but like udonkey said, I'm willing to reserve judgement till I see him play.