You won't believe how many hours we have lost troubleshooting SysV init and Upstart issues. systemd is so much better in every way, reliable parallel init with dependencies, proper handling of double forking, much easier to secure services (systemd-analyze security), proper timer handling (yay, no more cron), proper temporary file/directory handling, centralized logs, etc.

It improves on about every level compared to what came before. And no, nothing is perfect and you sometimes have to troubleshoot it.