[Q] i9305 4.3 to 4.4? Is it possible? topic

Is it possible to update to CM11 nightly (or any other 4.4 roms... I'm not familiar with the scene) from 4.3 stock?
I did install KNOX, and then removed it. And then the Samsung service reflashed the rom again. So I don't know about it anymore. Didn't install it since then.

My story:
As many of you already did, I also installed the new update. Read below if you are interested (but you probably know all this anyway.)
So. A few days ago Google+ started to eat up my battery. I disabled it in the Application Manager and did not have the updates installed either. But it just started. My usual battery life dropped to only a couple of hours at max.

So I fired up Google and it said I have to install the updates. So I did.
Nothing changed. Then I went into Google+, signed in, and then signed out.
Nothing changed.

So all in all, I have a piece of crappy brick that I can't use anymore.
Bit of a rant: You gotta love this. You buy an overpriced product and they f... you over a thousand times. App makers, Samsung (4.3 crapdate), and EVEN Google. Then why the hell would I even want Android ever again? Seriously. If I would have to buy a phone now, I would pick an iPhone, no matter how much it costs more. This is just unjustifiable. "Hey customer, thanks for buying our product. Now let us make it all crap." ... WHY?

So yeah. Now I have no choice but to lose warranty (which I already used a few times because this is REALLY a crap quality phone). Not that HTC One X was any better, it had a faulty GPU/motherboard like 4 times. (Thanks Nvidia!) ... Sorry guys, I'm just infuriated.
Wish I could just change the phone down. I was thinking about Sony, but if Google can buttrape you anytime, why bother? No guarantee I can just fix it on Sony either.