I have definitely jacked off to plenty of hot porn in my day. Some of it live action
Actually my first JO material was a Hustler magazine. I felt that was safe to have if anyone found it, because it was aimed at straight guys. But unlike Playboy and the like, it showed pictures of sex, which meant hard cocks. And that thrilled me. Plus one of the male models in particular really hit me as a really attractive man. So God bless Larry Flynt, wherever he may be!
But once I really started jerking it like every night in bed, I started to lean more heavily on my imagination. Over the years I've gone back and forth on this, especially when I had my own porn videos to watch (I hope it wasn't so much narcissism as it was being turned on because I was the kind of guy who got to be in porn!) or when I started watching bareback porn in the early '00s.
But my imagination tends to be far nastier and hotter and sexier than any porn scene. I have fantasies that will get me hard as a rock just thinking about them. So all in all, I'd say my imagination takes the win here.