I'm a trans guy who does not give a damn about gender in any form. I like lesbian porn with actual lesbians but hate lesbian porn where the women look like they're doing it for the money. It turns my stomach when it seems fake. I like straight porn with good looking guys (the women are always hot in straight porn; it's the men who tend to be ugly) and women who seem happy to be getting it on with them. And I love man on man porn because it's a rare thing for either of the participants to look unenthusiastic about the proceedings. I get turned off if one of the participants isn't erect, like boner-killing empathetic reaction.
The porn industry has a lot of skeletons in the closet regarding coercion, blackmail, and drug use to get performers on camera, and I can't feel comfortable and aroused watching stuff where I question the willingness of the participants.
That said, I read a lot of porn of all ilks. The written word lacks the squick factor of visual porn, though it's also less intensely arousing at times. As a published author of erotica, I try to bridge that gap a bit, but I admit that no matter how good books are, at some point I wanna see video.