In my opinion the best thing in mobile is both sim slot is 4g enabled, second thing is battery performance and its impressive look .Easy to use in daily life because it is thin & light in weight , also received marshmallow update a few days before .Earlier I used to get around 1.8 gb ram free but now its 1.4 -1.5 free most of time .Camera performance has deteriorated after the update .sound quality through the loudspeaker is pretty low . Unfortunately miui devs arent even caring about the bugs a bug fix ( really stable update is needed)