Didn't read his article word for word, but as a matter of argument the K3 refreshes EVERY page turn whereas the K4 comes defaulted to refresh after a few page turns. That can make a big difference between displayed screens even on the same K4. To test it where it is apples to apples, he needs to install FW 4.0.1 on the K4 and set the page refresh to EVERY page. Otherwise his tests are skewed and totally meaningless.

EDIT: I went back and read the article thoroughly and he never mentions the page refresh setting on the K4. I doubt he even thought about that setting. If anyone has a way to contact him they should pass this info to him.