I've been on with Rush and O'Reilly as well as some other national hosts. The Rush and O'Reilly depictions are pretty close. If you disagree intelligently with Rush and have your presentation in order and especially with published facts, you either wait endlessly on hold, all the while the screener keeps comoing back and saying "your next" and then 2 hours later the show is nearing the end when he'll finally say, we've moved on, except you continue to hear callers on the topic.
If you disagree but come off as a liberal loon, Rush with play with you like a cat plays with a mouse until he can go in for the attack just moments before the break. If you get through and he doesn't like where the conversation is going, you're muted until the commercial while he pontificates a point. They don't dump you, but you can hear him, but he and the audience can't hear you. I've even been accused of hanging up before while all the time not being able to respond.
I've also been in charming agreement and he'll keep you until moments before the break when he needs to make a close going into the break and you can no longer communicate.
Once in a while he'll let a intelligent diagreement caller stay on for a while, and that's usually when you'll see the comments here on FR about that caller and how they had Rush dancin. But it's not often.
Of course some of it is anecdotal to a point, but there is a lot of fact in his story.
On Rush's show, if you're a liberal loon, you get bumped toward the front of the line, even if you've called in half way through the show.
Ever listen to what a lib host does to a conservative caller? Take a listen to KGO after one in the morning.