Everything was already installed/synced/etc. I have had many phones over the months and no phone came close to sucking as bad as this did in the battery department right out of the gate.
Well, then you should have give it at least 10 charge/discharge cycles before trying another. A battery that has been exposed to heat is not going to work too well. But all you did was one or maybe two and then gave up.
I can also give you sources if you'd like of reports on battery life where z1 came close to last on every one. In fact, I searched the interwebs for almost 2 hours and not a single battery report actually gave the Z1/z1s anywhere above average. They were all below average if not the worst around compared to modern phones
There are plenty of sources here that will refute them wholesale. It ain't the battery.
So what happened ? t-mobile gives you just one day before they lock you into a 2 yr contract. It was too risky to wait longer and be stuck with it.
You can trade things in easy, the international lot are pretty much stuck with whatever we buy. And we buy the damn thing retail, no contract. A major decision.
So what are left with it now ? the note 3. there will be themed roms but no AOSP. I dumped samsung because exynos has even less development and i'm not a fan of this KNOX business. How dev friendly will that be.
That leaves you with the nexus 5. Decent camera. tweak heaven.