A lot of complaints I’ve seen is that it’s bloated - it’s not only a system manager but also has a DNS relay, network manager, container manager, and so on.
That said, codifying service startup and managing them with cgroups is IMO MUCH better than init scripts that think running killall apache is a good way to stop a service.
Re blue sky, is anyone actually federating with it? I don’t know of any other instances besides the official one.