I currently have an Xperia SP and i found the battery life to be pretty good for the tasks and routines i do everyday. It seems that Sony has properly optimised the OS and battery life on their phones this time.
But the biggest issue of my Xperia SP was the camera. Zoom is atrocious and near abysmal with lots of noise and artefacts. Burst mode and shot-to-shots/in-between shots was non-existent. Lag was a mile wide. ANY type of image stabilisation was just nothing.
Is the Z1 camera zoom unlike the SP's?