All I know is that topsider is NOT perfect for M119 engines (my E420).
I have to do it both ways! There is about half a quart left in the engine after sucking the oil out. I still use topsider b/c I don't care to have to drain 8-9 quarts entirely in a pan under the car.
I think, therefore, it very much depends on your engine/oil pan combination.
2005 CLK500 (conv)