The proof is indeed in the pudding. Like for most things, its much easier for me to wrap my head around it when there are bits I can break.
There's a lot of flexibility here for service control that sysadmins who have grown to rely on sysV init scripts are going to need to expend some energy learning to wrap their heads around some of the flexibility in control/resource limits that relying on cgroups allows. From a sysadmin pov, this seems like some of the richer benefits are going to be reaped in understanding that particular point of the design... as well as some of the biggest challenges. The discussion about how cgroup level interactions with screen-like detached behavior is going to be important.