The attempts so far to meet a middle ground haven't been all that successful due to censorship. Right now for games I think the problem is that typically games are either totally chaste, or non-stop sex. Sort of like say 'Dragon Age: Origins' with more payoff at the end of the romance subplots. Thus you will have sex scenes (including over the top ones) when appropriate to the game and it's progression. I tend to think that the future of adult video game entertainment will be when you see regular games developed without concerns over censorship. Not my genere of choice, but as I said I am slow to dismiss an entire genere out of hand. If it's simply a visual novel/adventure game, then it tends to not be especially good, in certain cases like the cult classic 'Knights Of Xentar' it can actually be fairly entertaining to the right audience.
A lot of it revolves around how much gameplay there is along with all the sex. While most are garbage there are a few out there that are fairly decent, albiet a lot of them don't come to the US.
I will go so far to say that while I have heard nothing really wonderful about the gameplay of THAT game in paticular, I am not so quick to insult all porn/hentai games. That should give you a pretty good impression of the game if your really curious. Here is a review of 'Rapelay' from Something Awful by someone who played it for the review.
