Phoronix has covered an article with backed up values. They came to the conclusion that: "Due to the user-space slowdown, the overall boot time with Fedora 18 is slower than with Fedora 17 from the Intel x86_64 systems that were used for this preliminary Fedora 18 benchmarking."
I confirm the Phoronix article and even beyond that, systemd doesn't behave as expected. Often it's required to enable or disable a service multiple times to have it either stay enabled or disabled. Even having remaining bits in