This works great. Can chill 5 gallons from boiling to ~100 in about half an hour with sink faucet water and recirculation

Really a time saver...had slight leakage problem as others have described here. When attaching hoses to the cooler, the connection not only has to be tight, but in the right place, not more than an inch from the intake and outflow ends.

I love it. True, copper conducts heat far better, but for the total surface area of the chiller I don't think it matters much. I stir the water as it chills to get much faster results, as the rate of heat flow from one material from another is proportional to the difference in temperature, so you want it touching the hottest liquid as much as possible. You can tell how much heat's getting pulled out by feeling the output end for how warm it is.

I've chilled about ten brews with this so far. Being stainless it shows no age. Somehow a hose clamp holding the two ends of the coil together broke off, but as far as I can tell the clamp served no purpose and I don't miss it.

This thing is amazing. Cooling 3 gal of wort in ice bath used to take 1.5 hours and 4 bags of ice. Only 20 mins with this to get to 80 degrees with water running at a trickle. I sent discharge into 2 gal watering pail to water the garden. Got about 15 gals of discharge. After reading way to many articles and reviews, went with stainless version. Free shipping with Prime also helped the decision. I stretched out the coils thinking there would be more efficient cooling if there was more space between the coils. This was a BIG mistake, don't do it. Once stretched out it was no longer totally submerged and impossible to flatten out again. Wish I could start over. Now itt's kind of like a Slinky and doesn't fit my pot as well. Dumb on my part.

I don't know what these folks are doing to get leaks, but I tested mine before brewing and with NO hose clamps, had no leaks. Got mighty cold, too in the 15 minute test run I gave it.

Besides, that, with SS I don't have to worry about ionization or corrosion of copper getting into my beer.