Using this Redmi 3S prime for last 2 month, I am very much satisfied with this MI product.
The main advantage is 3GB ram, from where every time I found 1.4 GB ram always free, which makes this phone Lag free and very smooth.
32 GB internal storage(ROM) is sufficient for normal daily use,
MI provides timely MIUI updates with new and interesting features(recently I found three finger swipe to take Screenshot)
Design is elegant but I was expected more stylish look.
Glass is not gorilla glass.so keep this in mind and use any good screen protector to avoid scratch mark.
Xiaomi never provide and headphone with mobiles, here also the same scenario.
Battery is excellent, 4100 Mah Li-po battery gives me 34 Hour backup(Talking, whatsapp, facebook, song, no game or video)
So far build quality and performance is good in this price range of 8999/-