quote; Does anyone really use CI anymore? Maybe a government office building? There are so many advanages to plastic: cost, ease of cutting, installation, labor, space requirements

The MAIN reason plastic is being used for drain and water pipes is because it is "cheaper", any other benefits are ancillary to that. It was the reason polybutylene, which ruined many contractors and insurance companies, was so popular from the 70s to the 90s. But when it started to fail, it took a lot of people with it. At this time, we do NOT know if PEX will be the "new" pb, only time will tell.