I'm using FreeBSD for servers and thankfully Gentoo remains on OpenRC. If they switch I'll move my home computers to FreeBSD too.
If I were choosing a "most interesting alternative to systemd and classic init" award, it'd go to GNU Shepherd which is the init system of GUIX as well: https://en.m.wikipedia.org/wiki/Guix_System_Distribution
All the talk about BSD and launchd has me thinking Shepherd might be on to something. Launchd is XMLed up from here to Sunday, whereas Shepherd can have all the benefits of Scheme's S-EXPRs being tree structures while also having a great scripting language (Scheme) at your disposal.
It was kind of like learning Unix after coming from a DOS background.
If FreeBSD switches to systemd, I'll stick with OpenBSD. OpenBSD is as likely to switch as they are to rewrite the kernel in rust and go.
TrueOS just started using OpenRC and seem happy with it so far.
I suggested to them back in January 2017 that since OpenRC has s6 integration, they might do well to add s6 to that to gain full service management. I never received a reply. I haven't heard that Laurent Bercot was contacted, either.
* https://news.ycombinator.com/item?id=13458186
* http://www.mail-archive.com/supervision@list.skarnet.org/msg...
I personally use the nosh system and service managers on FreeBSD and TrueOS, of course. I just wrote up a more detailed account of how I used them on TrueOS to run the PC-BSD desktop login and chooser utility under proper service management, and to improve several parts of that subsystem.