The change in speed is a nice side effect. But for systems that don't actually need a short boot-to-shell time (like anything except desktop or laptop installations), there is some more complexity during boot, especially with systemd.
Am I the only one who also considers ease-of-use a core feature? SysV init is quite easy to understand, and upstart is quite easy to use, too. But an admin actually needs to invest quite some time to fully understand all the systemd files...