IMHO I believe that the Topsider-type devices remove more oil than draining. There are 2 reasons: one is that the drain plug is not absolutely flush with the bottom of the oil pan, so leave about 1/8 inch or more oil in the sump. This is outlined in a recent tech article in The Star magazine. The second reason is that the suction devices allow you to suck the oil out of the filter chamber, so more oil is remved in this fashion. I get quite a bit extra out of each of my engines this way (I have 3 different engines in my cars, so my opinions are not limited to experience w/ one motor)
Mr. Bible? I KNOW you want to take issue with this
