I have. I ran Arch for 3 years, up until 3 months after they implemented systemd. It made a KISS situation incredible complex. I switched back to Debian on my desktop after that. If Debian switches to systemd, I'll switch to Slackware, until SystemD has proven iteself to be stable and simple to administer. Not before.
I've installed systemd on Debian testing months ago and have not had a single problem. https://wiki.debian.org/systemd has some hints.
I think it's likely when Jessie is released you'll most likely find that stuff still works.
