I hate plastic pipe in walls. I grew up in a hosue that is all copper lines, still in good condition even with ~ 30 years use so far with hard ground water. the line down the well, and the line running to house from the well location are both flexible plastic. For all that new designs seem good, i just can never trust any product with plasticizers that are lost over time. We deal with plastic and rubber items on elevators every day, many of which, with NO uv exposure, have started to break down, just been too many years. Of course, the old as the hills stuff with Bakelite and other materials, in some cases wooden backer boards that the relays all mount to on a huge rack, with the terminals just being bolts in the wood, still work 100% and have 0 issues.
