I have to say that this device never lags or feels slowed down by software.
It did had heating problems.I switched to Canvas A1 after this device because I was not satisfied with the 4inch display.In 2015( the year in which I changed my device) , 4inch were very small device compared to the competition which used to offer 5-5.5 inch screens.
Pros-Amazing build quality, very premium looks, very fluid software, good camera, good audio, good customer support from sony.Cons-No update aftee 4.3 jellybean, phone heats up too quickly, a small 4 inch screen