I ski the K2 Lotta Luv most regularly, which has a 78mm waist. That's pretty fat, at least compared to the old days, and is ample flotation in most (at least to knee-to-thigh-deep) conditions for a gal my size. That said, on deeper days I am a big fan of the Phat Luv, which is truly fat for females, at a 95mm girth. Good times to be had in the deeper stuff, and I found them to have a surprisingly good grip on frontside hardpack and good manueverability in tight spots.
BUT, I ski in CO and occasionally in CA and Canada and usually in back bowls type (in-resort, but not too maintained) conditions, not too many groomers and not a lot of ice. So I think I am definitely in the mid-fat --> really-fat market sweet spot.
I cut my teeth skiing in Michigan and on the ice coast, and I am not sure I would pick these skis out there. I skied one of the Rossi Oversize Models on a firm, frontside day last winter, and I think a recreational race ski or something more like this would be a lot more fun in someplace where I was dealing with more compressed snow on a daily basis. Ah, how I remember a few days at Loon where you could actually see the grass through the layer of blue ice covering the hill. Sharp skis with a skinny waist were called for. Or maybe just a hot chocolate in the lodge. You east coast ladies could show me up on the blue ice these days, I think!