This is one of the most dicussed topics on this board.
Do a search and you will find plenty of lengthy discussions on it.
Dennis, I believe the argument that stems from the topsider pulling more oil is that Mercedes designs the dipstick to be the lowest part of the pan and the drain plug may not be completely flush with the bottom.
1999 Dodge Ram 2500 Cummins Diesel
2002 Harley-Davidson Fatboy
Merlin Extralight w/ Campy Record