The contractor who built the house used I believe it was called copper "red"? it was the thinnest walled copper that could be used by code. Anyway after many pin hole leaks (we're on a well). The last straw was when we went away for a week end and the living room ceiling was on the floor due to a whole section giving way. So it was either start replacing section by section in new copper or go pex. Due to the flexibility it was easier to feed pex through the holes after we took the copper out in sections.

John 807