Share your experience!
By the way, now that I have flashed a Greek ftf, I will get updates released for Greece, right? Also will I get any updates from 3 UK?
Try uninstalling and disabling the apps you don't use.
I usually have around 250-300MB free RAM - pretty much the same as 4.1.2. I couldn't browse the internet and listen to music at the same time on 4.2.1., but it's not a problem on 4.3.
As long as apps aren't crashing out the numbers aren't that important.
You'll get Greek releases through PCC and SUS, not sure you get OTA updates from Three. Shouldn't cause you any problems though.
Something else Which might not be important but its interesting :
In antutu I got 23500 score where I used to get 20500 with 4.1 !
How can I disable preinstalled bloatware such as Facebook and other crap from Sony?
setting->apps->all
Built in stuff you uninstall updates, then disable. Other stuff you can just uninstall completely.
I did Antutu tests too (sad, but true!) - but they were very similar: 22421 for 4.1.2. and 22525 for the latest.
You should be able to do that by going into settings-apps-all-select the app you want and tap the disable button.Sometimes,first you need to uninstall updates.
LE:Guys,for you on 4.3 has better antutu result than 4.1.2?
at least for me yes
Nice 
so wherre can i download the Greek .201 and will i be able to flash it and use it on the phone as i do not speak Greek like you 
Greek ftf:
https://mega.co.nz/#!zpxhyQQL!Qqq5i5e7cCmdElpkGxZgYRYDUl_eLpQ6m2nGaBPXOK4
Not installed this myself, so at your own risk! Be sure to backup your original firmware and important data before you start.
It will display language selection on first boot (hopefully not in cyrillic!), just pick English (UK).
Excellent
Thanx blackbox 
Now that you have mentioned it indeed a bit risky indeed...maybe will wait a few days and see what sony comes up with ...in the meantime will download all i need and wait 