1. systemd runs as root, doesn't bother me that docker daemon does as well, since they do similar things (for me). Only users with access to the socket file have access.

2. I like the idea of not having a daemon but never actually had a problem with this in practice. The daemon has never crashed on me. systemd also has daemons that have also never crashed on me.

3. It's like 3 lines to install the official docker package. This is a non-issue for me.

Those do not sound like very meaningful advantages. Certainly not significant enough for me to want to switch from something that Just Works.

Thanks for the reply though. I'll be sticking with Docker.