I have 3 400's and one 500c all of which I've restored. I love them all, classic looks and a great warm sound that is hard to describe. I run them in separate rooms on a daily basis. They all sound great, currently using heresy 2's on one of the 400's, heresy one's on the 2nd 400, Pioneer hpm 60's on the third, and 2 pairs of HPM 100's on the 500c. The Pioneers seem to have a better bass response than the Heresy's but there's a presence to the Klipschs that only horns can give. That being said, I'd be hard pressed to say that any one is better than the other. Don't think you could wrong with either.
