I used this phone for the past two to three years and in my personal experience it was amazingly fast and responsive but as the time passed around a month , it started to slow down so I rooted it and flashed custom roms on it.then it worked fine however because of its old hardware and low specs I could not get that smooth experience.whatever its ui was great since it was running miui, I was getting many ota updates but did not get an update android lollipop, thats kind of disappointing.so I installed redmi 2 prime’s rom , it was running lollipop miui 8 but then my phone was lagging alot.so finally my experience with this phone was pretty owsome.