Extractors are fairly new. Here's the deal. First off, everyone should know that steam is amazing. I am not a scientist and I don't know how or why steam cleans like it does, but it has incredible cleaning power, especially when used with a apc first. The thing was, once you went ahead and steamed your surface (carpets/trim/windows/etc) what did you do? Well, most people just took a cloth and wiped off the surface, including the carpets, leaving a very wet surface. Extractors do two things. 1. They shoot HOT steam into and onto the carpet, bringing dirt up to the surface. 2. They EXTRACT. otherise known as suction, these new vaccums extract all of the dirty water, leaving an extremely clean carpet. To have a true hot water extractor, the extractor MUST have a heater in it. The old bissel, (i'm not sure which one you are using sean) simply has you put HOT TAP WATER into the tank, and then extract. The new Bissel little grean PROHEAT machine has a heater in it which keeps your hot water HOT. The key is heat, the hotter, more steamier you can get, the better. The last part is the extraction. Ok, 'nuff said. Sorry for the extremely long post. I can't wait to try the bissel pro heat.