Share your experience!
The update is crappy! I've found that Sony Mobile programmers are bunch of lazy craps.
After the update, I found the following illogical errors:
1. duplicate processes/files stored in the storage. both old version and new version exist in the storage!
2. non pre-installed apps do not work anymore or crash. I googled and many threads say that the system cache structure needs to be rebuilt as it's corrupt after update. so, we need to remove the system cache and reboot to let 4.3 rebuild the cache structure.
I hope Sony Mobile will roll out a minor update to fix these stupid illogical errors. Do your jobs right, Sony Mobile programmers! 
It's allredy rolled out a bugfix softwer, from yesterday.
So, does the update fix these errors?