I bought the Mityvac liquivac. There is a problem with the design. The pressure is retained by the use of a rubber stopper that inserts in the pour spout. This rubber stopper gets contaminated by oil and swells and it becomes impossible to remove. At that point you cannot clean out the interior and the unit can only be used to remove old fluids and can't be used to pump in new fluids.

I don't know about the Topsider, but I would not buy the Liquivac.