I've used the Heil PR30 and the PR40 with a VHT CL100 and a Bogner Uberschall. Both mics sounded great, kind of a cross between the lows/mids of an SM7 and the highs of a Sennheiser MD421. The PR30 has more midrange emphasis and the PR40 is more scooped sounding.
I think the PR30 is a great mic if you're going for a good high gain tone; it's really easy to get it sounding great.