I don't get the critiques that a mid-round guy can't just be big, fast and have a limited route tree. We've drafted rotational DTs in the third round for pete's sake. If a 6'5" receiver who can run 4.3 just runs flies and posts and we take him in the 4th, I'm damn good with that.
You can teach route running; you can't teach those measurables. And even if the route running never improves, stretching the D is still valuable.