No problem here on Xperia 10 dual sim I bought from you!
Actually, just for a change, i was quite delighted at how easily I updated to 4.3. The download and installation was quick, restarting seemed to take a while and almost appeared to go into a boot loop as I saw the Sony logo and unlocked boot loader warning, twice, but it started just fine.
I only noticed that vibration has ceased in one of my apps, but I have found the bug report for that and upvoted. Otherwise, I’m really happy with the OS and hardware, a massive upgrade (to me) from Jolla1.