Default Did I have to update?

Hi everyone
I need to know for last time
should I have to update to kitkat
Or still on 4.3 which better
And if I will update
Which one is better
Poland
Or
Germany
Or
France
And what's the things will not work
I heard the sd card will have a problem
And
S view cover will not work
Is that's true ?
I wanna to know
And I wanna your advice 😎

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