I would have to go with Kellly Andrews in this contest. She is definitely bigger and, based on picture #3, is firmer as well. I also think that she has very nice nipples for a 'big' girl; Madison's nipples are small and fade into her breasts. One contest Madison would win is an ass contest. She has a nice round, firm butt and outshines Kelly in this regard.
For those of you who have been on the board for a while, please note the Kelly had a titfight/catfight with Lucy Pinder some time agao and ran away with the votes.