I am posting my upgrade experience with 4.5. I have an Xperia 10 III with two different SIM cards installed that is my daily driver and an Xperia XA2 Ultra with NO SIM card that I only use for checking email, calendar, and web surfing at certain times. I will not use anything other than Sailfish and am overall pleased with the upgrade. I do have a few issues, though:
Battery drain is dramatically worse on both of my devices. I used to end each day with around 70% on my 10 III and now I end at 40%. The XA2 Ultra is not used as often but even idle drains 15-20% in a day.
My WhatsApp notification sound is extremely quiet now, it is not the normal Jolla chat notification. So I have to check for the light frequently or I’ll miss messages.
My 10 III stopped working at 100% during the update and had to be force rebooted with volume-up + power. No issue on the XA2 Ultra.
My Android icons on both devices disappeared at first reboot and re-appeared after 2 minutes, but in the wrong order and with my stacked Android apps moved out of their stacking.
That said, it’s improved several other things for me, most importantly the mobile hotspot on the 10 III is much more reliable, fast, and stable. In general mobile data issues have disappeared for me and I’m really happy with it. I use two different carriers from different countries and I’ve found it works great with both. Overall, I’m happy with the update and I’m not complaining. Sailfish is getting better and better with every release and every new device, I’m just sharing my experiences with others if it’s helpful.