I prefer the thong on the slender, fit woman. If she is highly-toned in that area, I think it looks good. Otherwise, she should wear the regular suit bottom. A medium-sized or larger butt . . or flabby/saggy at any size . . just isn't attractive. I think age is a factor too, as younger females have nice, clear skin, less cellulite and their butts are much more likely to be tight at a given weight than an older woman. Granted, a woman who competes competitively in a sport is likely to have a tighter body than other women her age.