The summary is essentially just that systemd is just a bit more elegant. Basically the (non gamed) votes had those two at the top, but in the end upstart had a few more pain points, and systemd had a few more features.

- SystemD parallelization is more automatic. - SystemD has built in logging for all managed processes. - SystemD has Socket Activation (start process on demand) - SystemD has more momentum in other major distros (Fedora, Arch) - etc..