system message bus units are created, but no user message bus units are created. Ones from arch seem to work fine: https://wiki.archlinux.org/index.php/Systemd/User#D-Bus Reproducible: Always
Taking care dbus upstream is ok with systemd integration, I am unsure about including them without upstream approval :/
If we're to bundle those, I think we should also provide some easy official way of setting the bus address for user sessions instead of spawning local instances like xinitrc does now.
By "address" are you referring to the dbus socket path? If so, I was under the impression that the default was: ${XDG_RUNTIME_DIR}/dbus/user_bus_socket and exported as environment variable DBUS_SESSION_BUS_ADDRESS
Please report this directly to upstream -> bugzilla.freedesktop.org