I have encountered none of these issues so far - I updated two J1 (for our son), 2 Xperia X (my own old back-up phone and our daughter's phone), a tablet, an Aquafish (out of curiosity) and my actual XA2 (without encryption) and the Xperia 10 (with encryption).

I didn't do any factory reset.

The Xperia 10 feels a little bit unstable (some unexpected reboots and initial hickups with Here maps when trying to choose the SD card as memory for downloaded maps, for instance, but that have gone by now). Plus, the Xperia 10 still has a bad stamina (unlike the XA2 which is great in that respect). But otherwise, everything appears to be fine