Boring interview, as usual with Gaider.
In my first playthrough, my straight BROWN male human mage went for the templars, so he had only met Dorian in the Chantry and then again at Haven, where he turned down his help to get into Redcliffe, and then finally he joined the party when Haven was attacked. Never got his personal quest, probably as a result of this path having almost no way to raise his approval. Plus his quest relies on you noticing Mother Giselle in the main room and NOT sitting in judgment before speaking to her. Obviously, sitting in judgment is one of the first things players would want to do, and so I didn't get Dorian's person quest.
The result? Dorian felt like a bland character throughout the game. He was a "good" Tevinter mage who wanted to help out and had some good leads. Big deal. He never really fit with any of the missions I was on. He sort of fit with the areas that dealt with Venatori or finding magical artifacts. He was a somewhat entertaining companion to have in the party because of his banter, especially with Sera. But other than that, he was basically like Blackwall after you find out he's really a nobody. Just some guy who is there.
As for his personality, it was just... off. My mage tried getting along with him, but his responses seemed illogical to me. Like, "Don't agree with me! I disapprove!" Oh, okay. The only part where I felt like he and my Inquisitor connected was when after the Temple of Mythal when he said that my Inquisitor has inspired him to go back and change Tevinter, and act on his feelings not just talk about it. I also had him in the final battle, because I felt like he hadn't done enough to help out, and I think he felt the same way. In the absence of In Hushed Whispers, his loyalties and abilities go untested most of the game, so there's not much reason to take him along.
All that said, if I hadn't read about his character before hand, I'd have had no idea he was homosexual. Well... maybe I would have suspected it, but that's it. There was never any "Zevran moment" where he approaches you.
I don't know if BioWare, or Gaider, or IGN, or anyone else would consider that a failure or a success, but I would consider that a success. If you're homosexual or bisexual, I don't want to know about it. And if I have to know about it, then I don't care about it. Just get the job done. Sera was the same way. Though I think she had some dialogue where she indicated she was homosexual. Nothing too blatant though. But Sera had enough interesting stuff about her where she showed to be an entertaining character. Dorian didn't have much else aside from different spells. What were his scenes anyway? One with receiving a letter about Felix's death? Oh, Felix... Felix... oh, that other guy from the Chantry? Oh, sorry to hear that he died. Alexius is dead too? Hmm. Guess going to the templars really was the best course of action.
So again, Dorian is a meh character. If IGN was going to give any character the "award" for being homosexual, it should have been Sera.