I first heard him about 10 years ago. I thought he was the biggest bombastic ass I'd ever heard, and very anti-woman too. I later realized most of that was tongue-in-cheek and self-parody. I do think at times he has had a vein of anti-woman in him, but he's moderated that some.
In the last few years, I've listened to him pretty regularly and like him a lot, and take what he says seriously. But mostly I love to listen to him skewer the pompous buffoons on the left.
I think the parodies are the best part of the Rush program. He has Paul shanklin do Tom Daschle, and James Carvile,Clinton. They make you LOL.