Anyone who can't get and maintain an erection should not be in porn. Period. I don't care how good looking the guy might be. Hell, there are a lot of uglies in porn who can't get it up--why were they cast at all?
(The only possible exception would be a simulated 'rape' scenario--in that case the 'victim' probably should not be erect! I don't think I've ever seen a 'rape fantasy' porno, so I don't know what they usually do.)
The limp dick that I particularly HATE: Kurt Stefano. He ruined tons of movies in the 1990s with his boring looks and always limp dick. Major studios like Falcon, too, so money wasn't an issue. WTF?! I hate Kurt Stefano with the heat of a thousand suns, and hope he has had a miserable life, since he was such a douchebag for doing all those lousy LIMP performances!
Some are just so goddamned UGLY that I don't understand how anyone would cast them in a porno--Matthew Rush, for example. First, I don't really go for the over-muscled type, but barring that, his face looks like it's from another species of creature. HE DOES NOT LOOK HUMAN. I don't know what gender that face belongs on, either. Is it the face of a female orangutan on an 'Incredible Hulk' body? Very disturbing, and NOT in a kinky or arousing way!
It's one thing to have 'regular' guys in porn, but hideously ugly non-humans with no redeeming quality at all? UGH!
As far as 'gay for pay' goes, I guess that applies to Ricky Sinz, but I have to give him credit for bottoming and at least attempting to seem like he really enjoys it. He always has a firm erection, and the dirty talk is nice. So I give him a pass. Kurt Wild is supposedly 'gay for pay' but he can't possibly be that good of an actor! Definitely likes cock--and cute as hell with an awesome tight body. I just wish he would tone down some of the whimpering a bit, but I give him an A for effort.
Crazy screamers turn me off. Michael Brandon, if you read this, please either learn to lower the pitch of your voice so you sound like a man when you scream, or stick a cock in your mouth and shut the fuck up when you come! Ridiculous antics and high-pitched screaming from that guy! (Speaking of ridiculous antics during a climax, how about the awful shaking/shuddering/screaming fits from Matt Summers in every movie he's been in? A pity, because he's cute, and has no trouble getting hard while being plowed, but that bullshit he does when he comes just turns me off completely.)
I love a vocal performer, but most can't pull it off, and probably shouldn't try. Sam Crockett was always awesome, Zak Spears used to be great (that deep voice of his is hot), and the classic seduction scene in the original Pizza Boy film was fantastic thanks largely to the sexy chatter of David Ashfield--his best performance by far.