Share your experience!
I updated to 4.3 and would like to share some observations to those wondering if they should update.
- Battery standby time is approximately 30% less so if battery is important to you I would recommend not updating. I have no idea why some people are saying their battery life doubled. I tested this in a controlled manner with no apps except default enabled and widgets removed. Battery life is definitely worse.
- Wifi signal is much better with at least 50% range increase. First time I've ever seen full signal without being directly infront of the router.
- The new UI is smoother/faster and games run with less stutter. There is a bit of delay opening things every so often but in general it feels very fluid. You will lose storage space and free RAM is less than before.
- I noticed new graphical effects in some games.
- Phone gets hot. I've never noticed this much heat on my SP before, even using the phone for light tasks the back of the phone gets warm.
- It's now very difficult to take a screenshot as you have to press voldown and power at same time which is awkward because of the button layout.
- Auto brightness is still completely broken
There is other relatively minor changes all round but in my opinion the only things worth updating for is the wifi improvement and smoother gaming, or just because you like having the latest android version. It's a shame the battery is even worse than before. Google/Sony really need to sort the high standby drain problem.
I have found batteray drain a lot better, especially overnight... only loses a few % when previevously if lost a lot more. No had any issue with. The whole thing runs quicker and smoother. But agree with the "ht and mis" method of gettign a screen shot
I would recomend to update , although I used "Flash" and flashed a greek unbranded version a week ago ( before UK unbranded came out), so dont know if that makea any difference.
Overnight my phone stays at the same battery level. I can achieve this by activating the airplane mode 
I have tried airplane mode but it still drains faster than before, its all android/google so turning off cellular and wifi won't help. Can you post a screenshot of the battery stats where it stays the same level overnight?
@bojofas what is a few %?
I could get my sp to drain only 3-4% overnight on 4.1.2 (8hours), but if I used playstore beforehand it would be about 15-20%. Now I see either 6-7% or 25%+ on 4.3. This is with everything the same as before, no apps running in background, just the phone doing its thing. I don't use my SP as main phone, mainly just do some tests with it so I'm very certain its worse. I will post comparison screenshot soon.
Here is standby comparison between 4.1.2 and 4.3. The screen on time on 4.3 was only 5 minutes but I gave it another 2 perfect battery to be fair.