Well, this is the first time I've even heard of it, & after reading that little bit from Wikipedia, I've gotta say that I'm a little curious.
Well, if you've got the stomach for it, I say go for it! It's not like it's a crap production or anything. In fact, quite the reverse: production values are high, writing is excelent, acting great (I watched the sub) and the art is fantastic. It tells a rather awful story, but it tells it exceedingly well. My main complaint, and perhaps this is what elevates this work to actual art, is that by viewing a piece in which the main sympathetic characters are the incestuous couple, we see their side of the story, and that makes the viewer feel like they are tacitly complicitious. Therein lies the squick. Watching the Legend of the Overfiend or something like that doesn't make you feel all that nasty, because it's securely in the third person context (not to mention that it's just downright silly). By contrast, the realism of Koi Kaze makes the viewer an accomplice, by placing him/her partially in the mind of the pervy main character, or at least showing the viewer the world through his eyes.
Great art, however, is usually the stuff that evokes much discomfort in the viewer because it engages him/her in a dialogue on a subject which is too charged to touch in any other context. This is why we consider the arts a priveleged commnications medium.