Galaxy S4 Active With 4.4.2 NH4 ( Options & Opinions For Updating Welcome )

Just got this att G4 ACTIVE On Str@ightT@lk
SGH-I537
BaseBand version = I537UCUCNH4
Build number = KOT49H.I537UCUCNH4
OTA updated To NH4. Never been rooted.
It fails to update any further to Lollipop.
After downloading the update it restarts and says Installing...... but before its done it reboots.
MESSAGE Update Failed "Software Update Interrupted"
I tried manual method, renaming the file to update.zip on SD and get this ERROR
"error tmp/sideload/package.zip status 7" During install
it wipes the phone and no update

Most guides pertain to NE3 , NH3
How does Having NH4 change things?
Options & Opinions For Updating NOROOT/ROOT Welcome

[Q] Opinions on this phone

Hi, I am planning on upgrading to this phone from my Z2 at some point in the near future. I was wondering if people who already have this phone could give me their opinion on it (pros and cons), what phone they had before it (preferably users of either the Z2, Z3, or Z3+/Z4), and how is the heat problem the S810 has.