yes the Xperia SP will get the 4.4.2 update around mid of July...
both device are equally good but in moto g you will not have a SD card expansion slot... that is only 16gb of memory..
also the battery backup of xperia sp is pretty good ...
and also the GPU is better as moto g run on adreno 305 gpu and the xperia sp runs on adreno 320
best of luck !!!