I believe our experience to be relatively unique, as factors not described here likely contributed to our experience, but I wanted others to be aware of potential conflicts.
After months of investigation, including tickets with both Google and PDQ support, I determined it was PDQ's package disabling auto-updates that caused some sort of conflict with other Google apps relying on Google Updater. Last spring we had an issue with Chrome taking 30-60 minutes to open on a fresh launch for most of our users.
