Product review (2 stars): definitely works...well for 3 years
Update: broke after 3 years.

I've had this for a month, and I've yet to wash in anything other than cold water. I do use detergent, but only about 1/5 as much and I don't wash as much. What I mean by that, is sometimes I would have to add an extra rinse because of heavy detergent use. Now I may do it, but it's rinsed with cold water so it's kind of used like I would use a prewash before. I do have to pre-treat stains as before, and I use about 1/4 as much bleach. My first load had a bit of an odd odor, not stinky,but different. I figured it was the 'ozone' odor. I've either gotten use to it, or the small detergent and softener I use takes care of it. I should mention my very first load was done ONLY with water. I still use only water on a simple load, well only water on the wash, but I always use a small amount of softener, so it's likely a combination of I have now gotten used to the odor and I smell the softener. Oh, your clothes will dry faster, I'd say 20% faster. I'm doing several estimations with this, but I am being honest and if anything, conservative with the estimates.

Update 12/29/13: I still love this thing. I wanted to clarify my comment regarding the odor however. As another reviewer stated, after the first load the odor was gone for good, and I've now realized it was the Purewash removing all the crud and chemicals that were present previously. I've only used my old method of washing once, and that was with severely dirty (from cleaning a mud soaked carpet) white towels. I used my sanitizing hot water temps and the same amount of bleach I did prior to this purchase. That was more for mental reasons. I'm sure if I had added a little extra bleach and my standard cold water I would have been fine, but one load with hot water after all this time is saying volumes!