To help the undecided cast their vote for Gonk, from Wookipedia...
Physical Perameters
Gonk Droid - 1.1 meters tall.
Mouse Droid - 25 centimeters.
Clearly being over four times the height (and even more so the weight) of the Mouse Droid, the Gonk has a massive advantage in terms of physical stature. The Mouse Droid has little to no chance of causing any harm to the Gonk and would likely have to rely completely on the Gonk tripping itself up or becoming confused in some way.
Use
Gonk power droids were effectively power generators with legs and a very simple artificial intelligence so they could understand rudimentary commands. They were commonly found on under-developed worlds that did not have an expansive power grid, or in mobile military operations.
The Mouse Droid stood about 25 centimeters tall and ran on four wheels. Although programmed with multiple capabilities, the droid was designed with only a singular function. A modular circuit matrix was installed beneath the droid's boxy shell, and contained programming for one skill. Commonly, mouse droids carried out cleanup and basic repair duties, and could serve in security and communications fields.
It also appears that the Gonk is more intelligent than the Mouse Droid, being able to follow commands, in essence allowing it to complete a large number of tasks and commands, whilst the mouse droid is limited to just the one command it is programmed with. Based on this, one could liken Gonk to the droid version of Batman, being more able to process battle tactics, skills and trickery in the field.