About the launchers and battery consumption, reflections of the "kettle".
Compare stock KOT49H,
Novaand
GEL.
Consumption increases in the specified order. Transparency - it is convenient, but not for free, affects the expenditure on the "Screen".
And GEL, if you do not turn on GoogleNow, IMHO is no better than Nova, and if you turn it on, then Google + WiFi services "eat up" the battery in 4-5 hours without additional. load.