So is this GNU/systemd?
GuixSD is kind of immature at the moment, and I have driver issues with linux-libre, but in the coming weeks I'll have the time to try to run it with a custom kernel that supports my hardware. If I succeed, as an Emacs user it'll become turtles all the way for me, which is very exciting (GuixSD is Guix + Shepherd + GNU + Linux Libre).
It is quite easy to overwrite the kernel package to use in a system configuration (e.g. to use a kernel with the RT patches applied), but I should say that I use the default kernel on all but one machine.