I personally agree with your thinking. I am a terminal, oil change fanatic. This was a subject about a month or so ago, and there were several people who believed that the topsider would get out more oil. I have a difficult time believing that, because it is sucking the oil from only one basic location in the bottom of the pan. There has to be a little film left over.
Keep in mind when considering my opinion, that my typical oil change method is coming in on Friday night with the engine at max temp, pulling the plug and filter, and letting it drain overnight, or maybe even until Sunday afternoon. The last drops that you manage to drain out of the engine, contain the worst of the sludge that you're trying to remove. Like I said, I'm an oil change fanatic. But it seems that long engine life goes along with it.
'84 Euro 240D, 516K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in