Mi4 was launched with 2 disadvantages.
1) No 4G facillity
2) Non Expandable memory and only 16gb memory
But other than this 2 difficulties the phone is a very good performer with snapdragon 801 3gb ram and stainless steel frame for reliability.
all in all a perfect phone for the price far better than mi4i which has lot of performance issues and only 2GB ram.
go for this phone if you don’t mind the above 2 disadvantage