This is from the Pro-Ears site and is certainly slanted a little bit, but they can't get away with misquoting specifications. It lists out what some of the competitive models have compared to their own products, and also goes into some of the how and why of electronic muffs.
http://www.pro-ears.com/FAQs.htm
It also shows I screwed up some of the specs in my first post, I should have known not to go from memory...