After a system update the indicators and the clock (wing panel) is taking a long time to appear, has anyone experienced something similar? Or know how to fix it?
I solved this problem by uninstalling the Parental Control plugin in System Settings:
sudo apt-get remove switchboard-plug-parental-controls
Not sure why.
Most likely the problem arises from the use of unstable repository ppa:elementary-os/daily. If you have no pressing need to use it, it is better to disable it. Install and use ppa-purge:
sudo apt-get install ppa-purge sudo ppa-purge ppa:elementary-os/daily
Also, you can remove unneeded packages (this is not required, but the packages are not needed when using a stable repository):
sudo apt-get purge apport apport-gtk apport-hooks-elementary apport-symptoms elementary-os-prerelease elementaryos-report-problem-dockitem evolution-data-server-google2 evolution-data-server-outlook evolution-data-server-pantheon-online-accounts fonts-opendyslexic gsignond gsignond-extension-pantheon gsignond-plugin-lastfm gsignond-plugin-oauth libaccounts-glib0 libgsignon-glib1 libgsignond-common0 libpantheon-online-accounts0 pantheon-online-accounts-plugin-lastfm python3-apport python3-problem-report screenshot-tool switchboard-plug-a11y switchboard-plug-mouse-touchpad switchboard-plug-networking switchboard-plug-parental-controls
In order to avoid problems, before you perform these commands, I recommend to use TimeShift.