Share your experience!
I'd suggest that you do a PC Companion phone repair, this will do a clean installation of the latest firmware and will also wipe your internal memory.
Open PC companion -> Support zone -> Phone/tablet software update -> Repair my phone/tablet (blue link style). Follow the steps given, do not connect your phone until prompted to press volume down while plugging USB cable.
http://www.sonymobile.com/gb/tools/pc-companion/
Also,you should have looked here:
/t5/Xperia-Z1-Z1s/Z1-issues-after-5-0-update/td-p/968554/page/16
I will lock this thread.