'icantdrive55 the thread is about water supply lines, not boilers or HVAC evaporator coils. I've dealt with a number of plumbers over the last several years, and not one wanted to use anything but PEX for supply lines. Actually a different preference would be a strike against any plumber I'd consider hiring for new work. Also you appear to be hellbanned.
Of course they wanted to use PEX. It's cheaper and easier for them to install, since they don't have to solder anything. But there are definitely some concerns about PEX. http://www.calpipes.org/ProtectingCalifornians_PEX.asp It leaches a lot of chemicals which may or may not be harmful, but which certainly do cause an odor. It is permeable to some pesticides, oil, gasoline, and benzene. It is not anti-microbial like copper is, which means you get biofilms. If it's exposed to sunlight for two weeks (perhaps because some contractor left it outside), its chlorine resistance disappears. It is not recyclable, and makes toxic smoke when it burns. But it is 1/3 the cost. Your choice.
