Do not listen to anything Pierre Sprey says, ever. I read Sprey’s essay, and it’s clear that it fails to offer any proof and in fact, offers the same standard lies about the F-35 as he spread about the F-22 earlier. Moreover, the essay reveals that Sprey is either completely ignorant about defense issues or, more likely, so biased against modern weapons that he’s blatantly lying to malign them while praising the F-16 to the highest. Why the F-16? Because Sprey, as a member of the Fighter Mafia, was one of the men behind that program and, throughout the 1970's and 1980's, he advocated its development and production. Sprey is, in short, the godfather of the F-16 as much as Harry Hillaker and John Boyd were. His love for his brainchild, the F-16, is obviously blinding him, leading him to malign better, more capable aircraft, including the F-22.
Against the F-22 Sprey went so far as to falsely claim that the F-22 is 30 times more expensive to acquire than the F-16 while being less capable. Anything that man says cannot be taken seriously.