I don't think this kind of book is for everyone. However, imo, "Bending" was interesting and insightful. Of course, there isn't much romance here ("Dear Marla" was sweet and really well written, though), but I found the whole experience fascinating, particularly the psychological aspect of it. This read like having a peek into someone else's escapist sexual fantasies bucketlist or running the whole gamut of a person's kinks. So obviously, it's very personal stuff (kudos to the author for daring to open at least a part of her secret garden, I don't think it's easy to do), full of unreasonable and insane ideas. Then again, not so crazy : it goes from tame to all kinds of shocking extremes, but hey, that's what fantasies are about, and it doesn't mean people want to or will act on it. And even if some people do, so what, as long as it's done right. Also, the author gives a fair and well-argued warning at the beginning for the thick-minded.
Anyway. Inevitably, some stories will seem weird (the unicorn one : intriguing but seriously, wtf ?) or perhaps will turn people off, but that is to be expected since some people like what some people don't and vice versa. Therefore, and also as a matter of respect, I don't think the book can be judged solely on that. Getting titillated is not even really the point here. It's more about reading "erotica" in the strictest sense of the word, as in, part of the whole array of human sexuality that can be more or less rationally explained, if at all.
That is how I know the writing was good, too. Because there are lots of things in here I'm not interested in, and still, somehow, the author managed to get across the page both the fact that her characters genuinely enjoy/get aroused by things and the fact that they understand perfectly the risks, consequences/are not completely stupid even if reckless, and all along, the story remains compelling. Another thing I found rather incredible was how the author managed to create a different atmosphere and feel to the different scenes depicted throughout the book : ominous, desperate, lighter, funny, etc. Overall, I thought this was an original book.