If I have to choose between a girl who is flabby with big boobs or a nice toned hottie with smaller ones, I will go with the latter. Many women with natural boobs tend to carry extra weight...myself included, so I am attracted to the exact opposite. Taller girls who are very toned, but not always busty.
Now if a girl is just a little bigger but firm, that's a go as well. My body may not be spinner by definition, but I am rock hard!