Well, I've read some pretty raunchy reviews before, I honestly did not enjoy them really. It was over the top, and this isn't an xxx rated porn site after all haha. For instance, this product
Fuck Me Silly to me is too far over the line, its very degrading and much more. (The product description that is, you may have to scroll down the page)
I think the key to reviews, is honesty. Don't put something in a review you don't feel should be there. I try to use more proper names rather than raunchy or dirties names. Rather than Cock Ring, i'll say Penis Ring. I hope the next few lines are not "over the line" but for example --- " I rammed this fuck plug so hard up my ass hole " I personally wouldn't want to read it quite like that in a review.
I'm not sure on specifics on what is over the line, i'm more speculating on a personal level. But when I write my reviews, I try to be professional with them while giving lots of detail, being honest and not turning it into xxx rated stuff