It did the opposite for me. It SLOWED ME DOWN.
When I arrived at the AKL, there was one CM at the online check in spot. He was occupied with a guest who was asking every question under the sun. I stood in line and waited while I watched people walk up to the 3 CM's manning the "regular" check in desks. Finaly I gave up and got in the "regular" line. When I got to the CM, he said "Oh, you did on line check in - your package is over there" pointing down to the far end of the counter (where the woman was still talking to the CM). He then walked over and got my package and gave me my keys. When I left the counter, the "Express" CM was still occupied with the guest.
Quite frankly, it is luck of the draw who you get in front of you. The "regular" process has never taken me more than 3 or 4 minutes once I get to a CM.
-dave