ESPN asks and answers a great question: could Dwight Freeney play in any era? It's largely accepted that he ushered in a new era of speedy, powerful pass rushers but could he hang with the old-timers?
When I look at Freeney, I see a guy who developed some moves, like the spin move. He's a little unorthodox. He does things that you didn't see a lot. He does it well. This is an era in which you get paid to get to the quarterback, and that's what he does. When you line up against most tackles, you know what they're going to do. He's going to bull rush me. With Freeney, he'll start outside and then spin inside. He has more moves than anyone I've seen play that position. He's a lot like John Randle.
Much as I love 93, and admire the breadth of his technique, it seems to me that he only truly becomes great after 1978--when teams started passing more and more. Put him in 1950 or 1970 and he'd be known as one of those guys who batters and sacks QBs and forces fumbles when the opportunity arises (20 drop-backs a game?), but in those days of two-back sets, they'd just run at him with a lead FB and neutralize his speed and penetation. On passing downs, he might well own the other team because those other eras are also before the advent of the giant balletic blind side protectors. He would race by those strong old fatties with vapor trails behind him. I think he'd have been viewed as a quality DE who could change the game with one big play, but who had some obvious holes in his game back then. Heck, a lot of detractors feel he has big holes even now, though I suspect that's system-based and overblown. Now a clever DC in 1960 might stack a DE/LB tweener behind him at OLB to keep the other team from running at his side all the time, and he'd be seen as much more effective suddenly....
Having seen this on ESPN with Peyton at #20 and Tebow at #19, I can safely say the list is a joke.
Freeney is a great pass rusher, but going back to when teams were predominantly run-based, I can think of more suitable DEs. Peppers would be one, JPP would be another.