Ranked in these QuestionsQuestion Ranking
Pro Default for many popular distributions
Systemd is the default init system for most popular Linux distributions (Arch, Debian, Ubuntu, openSUSE, Fedora, etc.) Therefore there is an insane amount of support behind Systemd. Choosing Systemd means running with the herd, which comes with it's pros and few (or none for some people) cons.
Pro Cgroups processes control
Systemd groups all processes by services using Linux's cgroups. Think about memory/cpu/tasks/IO/Net limits and accounting for any service.
Pro Login management out of the box
Systemd contains a daemon called logind which is used for managing user logins.
Con Not UNIX-like
One of the main argument that people who are against using systemd is that it does not follow on of UNIX'S core philosophies. 'Do one thing and do it well', instead systemd represents a collection of dozens of tightly coupled libraries. With responsibilities that exceed those of a simple init system because it also tries to handle things like device management, power management, mount points, cron, encryption, syslog, network configuration etc...
Con Makes dependent products difficult to port
Software dependent on systemd. Becomes difficult to port to systems that lack systemd.
Con Too monolithic
It tries to do too much. I don't think most people who use systemd are even aware of most of the features as they don't really use them. It makes it really complicated to deal with sometimes, and it's possible that in a few years this project will be a nightmare to maintain, and with that the users of it will start to feel the fallout.
Con Binary Logging
A binary log structure means that any tools you want to use to parse it will have to be aware of its format, and know how to deal with the ways it can become corrupted. Otherwise, it's not really possible in the easy sense.
Con Connects to Google DNS servers by default
Con Need glibc
Con Runs only on Linux
Con Not needed on the most systems
It is not useful or much faster than SysV-init on desktop or single-user systems.