I'm not too big of a fella (not scrawny, either - I am what most would call lean and fit), but I appreciate women of all sizes, including BBW.
I second the notion that I would never be with someone "in spite" of her size or have to "look past" her weight - hell no - if I am with someone, it's a given that she makes me stir between my legs and that's that. I'll show her off in public and ravage her in private.
Sexiness is not a number on the scale; sexiness is the confidence she exudes; her eyes, her lips, her smile, her wardrobe selections, the way she moves, and the way she expresses herself intellectually... among numerous other things that are irrelevant to weight.
Curves are a big part of my attraction to a woman's body. I love the feel of softness. To be blunt, I love big tits and fat asses.
I'll be honest - I think plenty of people are attracted to BBWs and they are reluctant to admit it. Sure, I would want a BBW to have a stunning face and be well put together, but I would desire the same from a slender or athletic woman. The media projects destructive (and sometimes disgusting) images of oftentimes anorexic women and tells us that is what we should want (to be or to fuck, depending on which side of the equation you are on.)
I think it is important to be physically healthy (for instance, an ex of mine had some health problems that were fixed by losing weight, so I encouraged her to do it - not so she could be "hotter" as I found her extremely sexy as she was, but so her life could be happier, easier, and more comfortable), but as long as you are, it's all good.