Failed after about one year
Last year I built a first floor laundry area and from day one was concerned about leaks. I was totally gung ho about the Intelliflow. The machines are under a counter and though I built cabinet/counter to be serviceable (counter can be removed) it is still a bit of work to get to it.

This week the Intelliflow failed after about one year in service. My plumber was out and we troubleshooted the living heck out of this - the line, hose, screens... everything is clear. The unit delivers hot, but only a trickle of cold. There is no debri in the unit. It is the unit that failed. Tomorrow my plumber is coming back to install a regular valve with a Burstbuster. The Burstbuster will not turn on/off with the machine, but it has leak detection and can be easily bypassed if there is a problem (so we are not without the ability to laundry for a week!). I have top notch hoses as well (Floodcheck - search for them, they do not have any kind of valve, just very well built).

Though I found a dealer who had a Intelliflow in stock and could pick up a new one today and be washing away the piles of clothes that have collected, I just can't depend on the product and wish I would have made this decision on day one.

Seems like a good idea, but the product is cheaply built. That is the problem.

Good product but fragile electronics
I have had two of these devices over the past two years. Installation is relatively easy, though you have to be careful to measure pipe lengths accurately -- as one would expect. The product works exactly as advertised.

My issue is that both of mine have failed electrically -- one occurred following a thunderstorm (though nothing else in the house failed), and one just out of the blue.

The second unit failed at 11 months, 15 days -- and Watts refunded the purchase price gracefully.

I will put a third unit in -- my laundry room is "convenient" on the second floor -- but a disaster just waiting to happen. At least I do not have teenagers loading up the washer until it overflows any more!

Don't use it with a newer High Efficiency front loader
My new Kenmore front loader has two cycles that cause the IntelliFlow to time out (Heavy Duty and Whitest Whites). If the cycle lasts too long, the device thinks the water has remained open too long and closes the valve. The washer is trying to do the final rinse cycle, but cannot obtain water. Because the washer is electronic, there's no way to just turn everything off, unplug the Intelliflow, and restart at the same point in the wash cycle (once turned off the washer must resume from start). The Watts people's workarounds do not help either. I'm trying to decide whether to have the plumber remove it or just settle for dingy clothes.

Saved my house and my back!
We installed this about a year ago, after my husband saw it on "This Old House." Like one of the other reviewers, my husband had some reservations about the plastic threads. When the plumber came to install it, he said one would have to be a real klutz to mess up plastic threads; in fact, he said, plastic threads are often more water-tight than metal. In any case, the plumber was so intrigued about the idea, that he only charged us half-time.
Before we installed the Watts valve, I had to reach over the top of the washer to manually turn off the valves. Now it's all automatic, and it's worked great. I see no reason why this won't work indefinetly. I love it!

Nice idea, flawed product
This sounds like the ideal solution to washing machine hoses which might burst at any time. It detects the electrical current of the washing machine and opens water valves only while the machine is active.

The problem is that the product is so cheaply made that its almost impossible to install correctly. The threaded attachments for the water supply are cheap soft PLASTIC. As soon as you start to thread on the BRASS nuts that hold the water connections tight, you will cross-thread the nuts. The maker knows of the problem since they have a warning "Don't cross-thread" in their instructions. A better solution would be to build a product with a METAL valve body which might actually survive installation.

Nice idea, but unless you are the most gifted installer STAY AWAY.