I have had one issue related to systemd; at one point when doing a routine update there was some dangling symlink issue that caused systemd to crash. This wasn't catastrophic; a lot of things didn't work, but I was able to cleanly save and exit out of applications, manually run a sync to make sure everything was flushed to disk, and then hard reboot.
systemd hasn't been without issue, but I've definitely had fewer issues with systemd than I did dealing with broken init scripts or upstart prior to moving to systemd.
This was the issue, I think: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=742322
systemd hasn't been without issue, but I've definitely had fewer issues with systemd than I did dealing with broken init scripts or upstart prior to moving to systemd.