I would have zero issues with KC taking Matt Barkley #1 overall. I could care less about past USC Quarterbacks, or if he measures 6'0/6'1/6'5 at the combine. Barkley is the posterchild for what the media does to a good player that stays in college too long. He was easily in the discussion with Luck and RGIII last year, and I feel the Redskins would have had a tough time choosing between the two. I think the draft last year goes Luck, RGIII and a trade-up for Matt Barkley at three. Unfortunately, he came back and has been picked apart by the Kipers of the world who question this or that, etc. Bottom line is Barkley has a TON of ability, and has the same chance to succeed in the NFL as Geno, Wilson, Bray, etc.
That being said, I don't think Barkley is the best QB in this draft IMO. But I wouldn't get upset in the least bit with the pick. No matter what Barkley did this year, it wouldn't have been enough. The moment he decided to go back for his Senior year, his stock was bound to plummet.