I wasn't much aware of MIUI initially. If not mistaken, it was MIUI 7 in my Redmi Note 3.  It was a great experience from that moment and its custom UI is always great. And now with my Redmi note 4, its good to experience MIUI 8 and now finally MIUI 9... (1) Split screen is the greatest change i have liked.. (2) The direct reply from notification and (3) the animated icons are awesome.......... Waiting for more.. and Best wishes to MIUI n its team