I just changed my oil using a Topsider and like Glen had no difficulties at all. I did notice that if I let the car sit for about 5 minutes after all the oil was sucked out I could pump even more oil out. It may be the check valve or just residual oil that is slowly draining down.
When I pulled my oil filter out I did it slowly and let any oil sitting in the filter canister drip out. I then used the topsider to remove the oil sitting in the housing and installed a new filter.
A trick to making oil changes easier is wearing rubber latex gloves. It insulates your fingers and makes changing it hot much easier.
02 C32 AMG
84 190E 2.3 5 Spd