I am using mi a1 since 3 months but so far I have not facing any problem so far. The built quality of this phone is superb, sleek design and looks good in hand.Battery performance is very good , software is good no lags so far , no heating problem .the performance of the phone is superb.the camera quality of both front and back is very good specially the 13 mp back camera working very good in day light and average in low light condition.the display qualith is very nice .the overall phone is very good in this price range.