You're being downvoted because this article is about the security of NTP implementations, yet your basis for recommending systemd-timesyncd is that it "works really well" for you. Well, ntpd worked well for me too but that didn't make it secure. You offer no basis for thinking systemd-timesyncd is secure, and yet there are many indications that it might be insecure: 1.) it's new, 2.) it wasn't designed with security in mind (unlike openntpd), and 3.) systemd's other reimplementation of a complex, hard-to-secure, UDP-based protocol (DNS) was discovered to lack even the most basic security protections[1].
Even someone who likes systemd's init system functionality should think really hard before using systemd's DNS and NTP appendages. This kind of stuff needs the attention of security experts. It can't just be reimplemented as an afterthought and be secure.
It being a simple NTP client and not a server means that it has a vastly reduced attack surface. That's good. But that doesn't mean we shouldn't wait and see how buggy it actually is.
And their named DNS daemon was to be a stub resolver. Then it grew a cache. And now it seems to have developed a insecurity that most other DNS daemons out there dealt with a decade ago...
Even someone who likes systemd's init system functionality should think really hard before using systemd's DNS and NTP appendages. This kind of stuff needs the attention of security experts. It can't just be reimplemented as an afterthought and be secure.
[1] http://seclists.org/oss-sec/2014/q4/592