I'm late to the party but...Copper is a great, tried and true product if you have a municipal water supply. If you have well water, l would recommend pex 9 times out of 10. Also if you bid new construction jobs in copper and your competitors bids are for pex, you will be home alot. Viega makes a product called fosta pex(FormStay) that has an aluminum jacket on the outside of the pipe that holds its shape really well and can be used on potable water as well as in heating systems. Cpvc water piping is shit in my professional opinion. Pvc is a great material for drain piping. If its installed properly it will outlast the building.