I just installed Linux Mint 17.1 Cinnamon (Rebecca release) on the machine I'm typing from this week. While it does have some things I don't like (some weird config location choices, /var/run, /etc/bash.bashrc, bash_completiond,WTF is up with dnsmasq?, some weird sound behavior, semi-broken bash tab completion, won't mount my cellphone no matter what, etc - aka issues I've never had with CentOS).
I also still have 2 several years old but up to date CentOS boxes I use every day and prefer them but I picked Mint because it's supposed to be better for day to day regular desktop use, has far more up to date packages, and I was tired of fighting dependency hell with extra packages from 2008 (my own fault, admittedly) for things like VLC.
My understanding, and I can't find where I read it before I went and downloaded/installed it, is that Mint is in wait-and-see mode and will be waiting until their next LTS release in a few years and then re-evaluating whether to switch to systemd. Looking at the system I have installed right now, it looks like there are a few pieces installed for compatibility (although none of them are running) but the init system is still old school init.d and runlevels.
I haven't looked at systemd in depth but my gut feeling is it throws away the UNIX mindset of, do one thing and do it well, output/input everything in text in favor of aping Apple (paritcularly)/Microsoft and the politics behind it seem dirty. I have watched a few Poettering videos and he comes off as a massively arrogant douche bag (but I am a fan of Linus and RMS so *shrug*).