Just off the top of my head I'd say that Janoris Jenkins at the top of the 2nd round was the most recent example of an elite talent slipping. Although we all know why. He was easily a top 10 talent (clean).
The Okafor scenario is pretty cut and dry. I have a higher grade on Okafor as opposed to Bostic. Secondly, we're factoring impact here. A pass rusher affects the game more than an inside linebacker is able to.
All of this is actually much more complicated when it's being explain in detail in my opinion, because my mind automatically calculates all of these factors instantly without conscious effort. Particularly the intangible factors of impact, positional value, etc.
Last year, my buddies and I had pretty heated arguments as to who was the better player between Jenkins and Gilmore. Felt like I was on crazy pills. I get what you're saying about the explanation making it seem more complicated than it is. Thanks, Slimm.