Our company introduced this last year. The reactions ranged from "the fuck you think I'm going to do this" to "you bunch of whiners, when I did Ops I was on call 25/8/370 for $0". The way teams implemented it ranged from "you have that week to work on whatever you want/not show up" to "well we don't expect any out of hours calls so we won't implement anything except a roster". It's been fascinating.