Doujin or Original Hentai?

When it comes to hentai manga there are two fields: the Original; stories and characters, all created by the Mangakas' imagination. The Doujin; a hentai work created by a mangaka (usually a newbie) using characters based off of other mangaka, usually popular/mainstream characters and settings. Which do you prefer?

I personally like original hentai because it shows the mangakas' imagination and creativity. He has to come up with (somewhat) believable settings, characters, and stories. It also lets me appreciate it more because the mangaka is not relying on popular characters for recognition nor as a start-up. When it comes to Doujin I find it hard to get into it, especially if the characters are non-original. Seeing non-orginal characters (such as "Shonen Jump" characters) in sexual situations is a turn-off.

Edit: I know not all doujinshi are un-original, my question is mostly at hentai with copyright characters (like "Naruto" hentai doujinshi).

While I usually prefer original hentai manga, I must say that I see a great importance in unoriginal doujinshis. I think it's basically a great way for us readers to see our favorite characters take a step in their relationships that we would never see in the original material, mainly because it is such a taboo, apparently, for authors to let their characters get actual normal relationships.

There's of course a lot of doujinshis which couldn't actually coexist with the original material, I don't enjoy those as much.

That is quite true when it comes to seeing characters we like and seeing how their relationship develops or is taken to the next level. In the original work, particularly in the shonen genre, the authors just mention their confirmed relationship and the development is glossed over. It can sometimes feel like a disappointment when the ship you rooted for, almost since the beginning and was hinted by the author, is not given up to our expectations.

Just so you know, the term doujin has nothing to do with the content of the work. Manga is the broad term that encompasses all of it, and doujin is a subset. Doujin is used to describe self-published manga. The stuff that's sold at a convention, without approval from any of those publishers like Wanimagazine. Such organizations can't try to publish parody works as that IP belongs to someone else, so parodies can only exist as doujin releases.

Sorry if I'm nitpicking but the community frequently uses the term doujin as the umbrella term for hentai manga but it's actually the other way around.

As for your question, I prefer original works. Parodies can be great, but I think my favorite artists really shine when they make original stories.