Mechanically formed tee connections allow branches to be formed faster and usually result in a lower installed system cost. Copper tube does not require the heavy thickness of threaded pipe with the same internal diameter, such as in natural gas distribution systems. Thus, copper costs less to transport, handles more easily, and takes less space when installed. Since copper is light and rigid, it doesn't sag over long runs, and it requires few supports. Overly aggressive water, not properly treated, may cause copper corrosion.
Copper tube is governed by established product standards and marked with permanent identification.
Contractors and inspectors always know what the material is and which company made it. Copper is accepted by virtually all plumbing codes. And it can withstand repeated freeze-thaw cycles, although, of course, no plumbing should be allowed to freeze. The company has supplied tubing in luxury homes for scores of actors, politicians, entertainers, manufacturers, architects, federal agencies and the military throughout California and other western states, including Alaska and Hawaii, and American Samoa. Copper is a noble metal that has never changed, and I have never had a failure.