In my opinion, sex scenes in anime (not hentai) are bad for the industry.
Why? There are tons of sex scenes in romance movies and tv series.
i think they are quite important, it makes the ending more fullfilling. However, i dont think its a necessety for it to be as graphic as this. just knowing they did it, or were going to is enough. But what kind of positions are they using? isn't it supposed to be their first time? In the first arc he used missionary, which is normal and simple, but the one he used now was one used by experienced people. But whatever, i guess this is just the way it is in anime, and especially eroges, like the one this is based on.
One i haven't played, ill download it and give it a try, maybe its better than the anime...