Eh, I saw some of that...

I don't think there's much of it, only saw it briefly when there was a board for it on not4chan. To tell you the truth I can't really remember anything about whatever it was, most of it was isolated pics (and some that were a bit disturbing, and for me that's saying something) because I don't think they make much manga of it.

Personally, I prefer normal H and loli-H and straight-shota (with loli or adult ladies) mostly. Toddlerkon is just really too young to be believable, but in art everyone's free to explore what they want, and no matter what the genre there are often some really great artists and writers. Oddly enough, the storylines of some hentai mangas are very good and complex and interesting, you never really see this with pornography movies. I think it's because of the painstaking labour that goes into making images, writing a plot seems like no time at all in comparison. Compared to fast live shoots and hack writers throwing crap together for director deadlines.

Of course, I like non-hentai manga most of all :p and even more than that, anime, since it has sounds and moving pictures and colour. Anime H is pretty cool sometimes too, Words Worth for example.