Here is a cool article on Jonathan Vilma from Sports Illustrated. Here is a quote...

"All I can say is thank you Mickey (Loomis, the Saints general manager), thank you Mr. (Tom) Benson (the Saints' owner), thank you Sean Payton," Vilma said. "They make your job a whole lot easier. In a 3-4, linemen get to the second level a lot faster so they want bigger linebackers who can take them on, sit there and hold the point. Guys 250, 260.

"In the 4-3 you want quicker guys who can penetrate and create a new line of scrimmage behind the original one. I wanted to be part of the Jets' 3-4 scheme but it didn't work out. I think I could have played it but it was going to take some time to get adjusted. I didn't get that time."