I’ve updated my Z2 last week to 5.02…this update went to ‘plan’…my last update (to 4.4) was very bad – after the update, the phone drained very quickly and things just stopped working properly – only way to fix it was a ‘Repair’ via the Sony desktop app – but after that, you need to install all the apps you had – easy enough to do when you login to Google Play and view all the apps you had installed.
If you are getting any strangeness, I’d suggest doing a Repair – it basically wipes the phone of everything and reinstall a fresh copy of whatever the latest Android version is – it then sets it as a blank phone, you then do a restore of all your data AFTER you have reinstalled all your apps (otherwise not everything is restored).
I’ve had no issues with my phone with the latest update though and it seems to be working better than I expected with the new update.