Some people can bench press 315 pounds within 2 seconds, and yet, they can't even budge 320... It really varies from lifter to lifter. I understand that there max attempts are naturally slow, but people are different. Why do you think Simmons popularized the "dynamic effort method"?
And as I said before, some guys lift their first rep in their five rep maxes like it's a max attempt, while others lift their one rep maxes as if they were doing their DE workout. Check out Kennelly's bench: http://www.youtube.com/watch?v=c7NRwF9KWIY
It took him less than one second to skyrocket that thing up and yet, he failed at his 1100 pound bench press attempt. It takes me two seconds to finish a lift with my 5RM front squat, he on the other hand takes him 1 second to lift his absolute max with the bench press. He is a "hit or miss" type of guy while Rychlak on the other hand (http://www.youtube.com/watch?v=c7NRwF9KWIY) can grind out more than Kennelly.
It really has alot to do with the "neural drive" that would take a long paragraph for me to explain to you guys.