I am starting to dive into a kitchen remodel of my house and need to put in a new drain and vent stack for the kitchen sink. The house is 1920's and the existing waste line is cast iron. I originally thought that I would use a coupling to attach PVC to the existing run. While I was researching I noticed that the cast iron distributors were really pushing the benefits of cast Iron pipe, especially with the new hubless fittings.

Why is PVC preferred over Cast Iron? is it anything significant?