Ferrer would have reached the SF in 2005 if he did not run into Nadal. Remmeber how far did Del Potro go when he run into Nadal at RG?
I admit that Ferrer has had a RG problem, where all the good play he had done during the clay season did not materialize in RG. But for the surface in general, he is much better than Berdych and Del Potro. And I am sure you did not forget that decisive Davis Cup match on clay.
What? If he was in Federer's quarter instead of Nadal, he'd have lost. Hardly likely he'd beat Puerta or Davydenko either. Del Potro only played Nadal at RG once when he was 18yo, still put up a much better fight than Ferrer, not that that is saying much.
You have to be kidding, Del Potro was a few points away from being a Roland Garros champion; well not really, but he'd have been the clear favorite for the final against Soderling had he managed to put away Federer. He's far more threatening to all of Federer, Nadal and Djokovic than Ferrer. Berdych, I concede, is almost as non-threatening to Djokovic and Nadal as Ferrer on clay, but infinitely more threatening to Federer.