It sounds as if you are biased toward copper. The labor savings alone makes PEX the least expensive of any material and with the price of copper today, PEX is overall less expensive.
PEX and other plastics are better for water quality because unlike copper nothing in water can harm plastic and plastics are inert, they don't add anything to water, again, unlike copper does.
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Imagine that, someone calling me biased
Not really though. I do like to explore all sides of an argument and a product though. Many see PEX as the greatest thing to happen to piping since copper replaced galvanized. Make no mistake, I am not against pex. My company installs miles and miles of it for both domestic water supply and radiant heat. However, I do like to keep an ear to the ground so to speak and I do like to research the crap out of something before I decide to use it. After all the research I have done, i have decided that Uponor has the best warranty, the best flow rate and the best fitting and connection system.
How's that for biased?