Xiaomi mi a1 is good phone with good camera and stock android . It is medium size phone and if you like medium size phones then this is one of the option for you.it has 5.5 inch display which fits in your hand .fast charging is also provided which is very important who wants to charge their phones very fast they can think about this phone. Processor of snapdragon 625 is provided which makes you phone run and load apps very fast. The basic difference between mi a1 and mi a2 is of display difference.mi a1 is medium size phone where as mi a2 is of bigger display.
So make your choice and mi a1 is good option for you