Yeah, although Regina is extremely powerful, I think that IF Rumple simply manipulated Regina into enacting the curse so he wouldn’t have to give up the thing he loved most (which I think is what happened), then Rumple’s power to manipulate Regina in itself tells me that Rumple is more powerful.
BUT it could just be another ploy, and Regina is double-double-crossing him 😉
As to who physically has more power, I’d say Rumple as of right now. But if Regina were to ever get hold of Rumple’s dagger, or if we found out that she was a Dark One or something…