Share your experience!
You can use manual mode and change the settings as you please, I don't understand the issue.
I totally agree with you, I love the Z2's camera
But I also have the same problem as you since updating my phone to 4.4.4 actuallu. The laggy movement you get in the camera when moving the phone.
my xperia z2 camera quality is lower than a normal 8mp camera. picx become grainy in half zoom itself.
i don't know whether its only my cam's pblm.
someoneplz answer my concern 
Does the camera lens has scratches or is it dirty? could you elaborate on the issue?
Settings > apps > all > camera > clear data > restart the phone