I think everyone can agree that "better" is a very subjective target....
That said, I think that RS is a more detailed piece, and certainly more of a challenge for the SS quality process. Neither of which make the piece "better" necessarily.
Both pieces depict powerful women, both having displayed their badassery on their enemies. Both have beautiful portraits, and let's face it, Captain Marvel's uniform leaves nothing to the imagination
I think it's a tough call having to pick just one.