Product review (4 stars): Decent product, based on my experience
I've been using the PureWash in my front-loader for three or four months now, with mostly good results.

The main positives in my experience:

1) It's easy to install, so long as you can get at the cold water line that feeds your washer, and so long as you can get by without installing a prefilter on the water line. (More about that, below.)

2) It takes only about 60 watts to operate, and it operates only while the machine fills, so the energy costs are minimal.

3) The washer runs on just cold water, avoiding the cost of heating water for laundry. This is a major money saver, depending on the volume of water involved.

4) No more detergent and fabric softener resides in the clothing or in the machine. My machine had begun to build up a brownish film in certain areas, but after using the PureWash for a while, that gradually disappeared. In fact, after the first couple of uses, there was some of this crud collecting in the tub, and I needed to wipe it out -- it probably came from the inner parts of the washer. It did take several washings of old towels in the PureWash water before they stopped being crispy from old detergent residues left in them from earlier days. (I haven't used fabric softener for a long time, since the residues mess with my skin, and I don't use dryer sheets for the same reason, so old towels were getting crispy in the drier.)

5) After multiple washings in PureWash water, some of the brownish stains from body oils on older whites disappeared. I had never been able to get those out before with detergent and clorine-free bleach. Underarm odors are also pretty well removed -- much better than with unscented detergent.

6) It's great not to have more detergent gunk sent off to my septic system to muck up the works there. Septic systems are very expensive to fix once they get plugged up with hardened chemical residues. We're talking about real money here.

7) After they've been washed several times with PureWash, stuff comes out of the dryer soft, without using any dryer sheets. (If you look into the chemical composition of dryer sheets, you'll not want to keep using them on anything you put next to your skin.)

8) If for some reason you want to wash something without using the PureWash system, you can just unplug it from the electrical supply to turn it off.

However, there are some negatives as well:

1) The PureWash generates ozone in the wash and rinse water. Ozone is great as an odor-remover and cleaner, just as PureWash advertises, but it is not going to stay just inside the washer, since washers are not air tight. Ozone is toxic to breathe, in high concentrations. My laundry room is about 100 square feet, with poor air circulation, and I could definitely smell the ozone in the air, and it was not the nice, fresh smell of the outdoors after a rainstorm, because it was much stronger. So, I set up a professional ozone meter and found that the ozone levels never exceeded the "short term" limits set by the feds for worker exposure, but did exceed the limits for 8-hour exposure by 50% toward the end of washing the first load. I found the levels irritating. Running the dryer quickly solves the problem, by sucking air out of the room, so it is possible to do one load after another by timing things right.

2) Whites do not get as white as washing with regular chlorine bleach (if you can stand to use that dangerous clothing-eating stuff). Perhaps that is due to the chemical composition of my water.

3) Buyers need to be aware that the hydroxyl and ozone produced by the PureWash will react negatively with certain chemicals in the water supply coming into the washer. PureWash recommends installing a prefilter, but I did not install one, since my wash water is free of sediment, free of chlorine, and free of rust and dissolved metals. (I have a well, and my water is all treated as it comes into the house.)  I think the successful use of the PureWash depends on getting interfering chemicals out of the water. Since my water is highly softened, I think I'm getting some interaction between the softening ions and the PureWash water, since there is a tendency to get a little goo building up in the washer. This problem seems to be solved by rinsing the clothes an extra time with the PureWash unplugged, before they go off to the dryer.

4) Initial PureWash washings of items that have been washed repeatedly in detergents in the past may not be entirely good, since there are likely to be some undesireable byproducts produced when the PureWash water reacts with detergent residues. I'm not talking about damage to the washed items, but rather things like odd smells, or a little slippery-feeling residue that might irritate sensitive skin a little. This is a fairly minor issue for me, that gradually went away as the items were washed again.

I know some people say they put a little detergent into their wash water even when using the PureWash. That seems to me to be a bad idea. If there is some reason you want to use detergent, then use it in a separate washing with the PureWash unplugged.

The bottom line: using PureWash takes some adjusting of old habits, might take some effort, but the end result is well worth it, to me. Of course, if the PureWash machine were to break down in the first year, I'd change my mind, but so far, so good.