What Are The Differences Between Samsung Firmware Version For Countries In The Same Region? Sorry for the dumb question - I really am a noob at this.
I have just bought a brand new SIM-free Galaxy S4 Mini LTE GT-i9195.
I am in the UK, but the phone has French CSC installed (code XEF).

From Handset:


Baseband version I9195XXUBMJ7
Build number JDQ39.I9195XXUMBJ7
SELinux status - enforcing SEPF_GT-I9195_4.2.2_002


Instead of upgrading via Kies to latest XEF firmware version, I was thinking of trying to use Odin to install latest UK version instead:I9195XXUBML4_I9195YTUBNA2_BTU.zip

Question

Any potential benefits / downsides to switching from XEF to BTU firmware version?
I guess that they are optimized for a particular country for example they will use different wifi channels (you should find the best channel anyway for best speed) and for different mobile communication infrastructures.

The best you can do to find out is test them.If you want the best out of your phone then flash a 4.4.2 or newer if possible rom and kernel and more (I use dorimanx 10 bet test)