Valdez is a natural Featherweight. And besides that upset against Berchelt, which now doesnt seem as impressive since Berchelt looks like complete shit, his 130 run hasn't been very good. Got dropped by Adam Lopez in the 2nd rd who was a last minute replacement, and won the fight on a stoppage that shouldnt have been stopped in a very close fight, beats Jayson Velez, the Berchelt fight, and the Robson fight were he didnt look so good.
Valdez best was at 126, and even there he was getting dropped by lesser comp and smaller guys.
The Stevenson knocked down was more of a balance issue, I'm pretty sure the shot landed on his glove and wasnt even clean. Having said that, 130 is one of the weakest classes at the moment, and I dont see someone like Shakur running through 135 like other ppl claimed. His size is probably a natural 135lb but do we really think he beats a guy like Tank?