I have them around the same power but Great Ape is inefficient for fighting and Goku has no control over the form. Those factors coupled with Taopaipai's small power advantage + Dodonpa, I personally say Taopaipai wins.
Goku. He killed Gohan. Although you could make the argument that Gohan did some training with in the Afterlife but Goku most likely trained just as much. Also I would think Goku being a growing boy while Gohan being in an old man body that's likely past it's prime would more than even out their gains even if Gohan trained more.