I do not think using the electric pump is as clean and as convenient as using the Topsider.
Use the hanging method, you can finish the job and pack the Topsider away without a drop of motor oil on the floor. It will be hard to do with a small electrical pump because both ends of the pump are open and oil is still inside the pump when done. If the electrical pump is small, you may have to baby sit it: holding it and wail until it is done and turn the power off. With the Topsider, you just pump it and walk away to do something else.
I used to keep putting off changing motor oil and filters. But with the Topsider now, oil change is usually on schedule.