Exactly the same issue on Cinnamon. Cinnamon starts very long and I can see following in xsession log:
Error creating proxy: Error calling StartServiceByName org.gtk.vfs.UDisks2VolumeMonitor Timeout was reached However, Cinnamon finally boots after timeout. But, as somebody mentioned above, all unneceassary devices like systemd are visible in file manager. Please make this bug serious. For now, need to downgrade udisks2 to Testing version.
