Comment 7 for bug 1584604

I also have the same symptoms (Kubuntu 16.04, all packages up to date):

Upon login the progress bar fills quickly (3-4 seconds to reach 100%) and then there is a long pause (>20 seconds) before the desktop finally appears. However, when I run systemd-analyze blame there is no obvious culprit:

           876ms systemd-rfkill.service
           338ms dev-sda1.device
           222ms networking.service
           199ms ModemManager.service
           195ms accounts-daemon.service
           171ms gpu-manager.service
           162ms thermald.service
           161ms NetworkManager.service
           145ms upower.service
           145ms grub-common.service
           143ms plymouth-quit.service
           134ms systemd-logind.service
           129ms avahi-daemon.service
           105ms irqbalance.service
           104ms preload.service
            92ms apport.service

I would be happy to provide more information, to help get rid of this annoyance.