Samsung Galaxy S3 FW Update Question

Hi all! first sorry if I'm posting it in the wrong section..

Ok well my sister bought a brand new Galaxy S5 and she gave me her old S3 and I am pretty much excited about it as I finally jumped for my old iPhone 3GS to S3

Ok so here's the thing! right now the S3 is on the 4.1.2 (Jellybean) and I search a little over the net and found out that Samsung announced that the S3 will not support the latest FW 4.4 (KitKat). When I go to check for updates my phone starts to download the update which is about 500MB in size and I believe it's the FW 4.3 update and I heard from some people and even googled it that the 4.3 update has a lot of bugs especially the consumption of battery which increases crazily.

Now I need advise that should I update my phone or use it on the FW I have right now? or Update and factory reset it which will erase all the content from the phone and make it as fresh as a new set which I believe might cure those problems? HELP!

I would factory reset the phone before doing a firmware upgrade.

I never noticed any negative effects of the 4.3 update on my s4. 4.3 just addressed a few issues and added the ability to use the galaxy gear.

id root the phone and install the 4.4.2 update yourself. I saw about a 30% gain in battery performance when it came out!