I'll start with the most important part of a hentai, the art. With just enough diversity they created one of the best looking casts of porn actors without too many oversized body parts. The animation has a bit too many morphs here and there. But to make up for that, the speed ups and close ups can queue in at the perfect moment.
While the story does have a couple holes, it is intriguing. Some say a story is worthless in porn, I say it can add a lot of meaning to the sex scenes and thus allowing you to feel more immersed. At the end of the day it is just a bunch of stereotypes clashing against each other, so it only works if you turn your brain off. Which just so happens what you do while watching hentai.
Overall, I would say the sound blends in well but just like the voice acting it is nothing special.
Finally, this piece is definitely not something you want to miss as an anime fan. Because to this day, hentai is still a part of anime.
