There are quite lot of mixed feelings about redmi 1s. It was launched to compete with Motorola moto e at comparable price. The phone is lag free for daily use and bettery doesn’t last longer than 6 hours contineous use. You should always enclose your redmi 1s with a back cover because the design of the phone is not robust. Even a 3 feet free fall of redmi 1s will get shattered. Its runs on MIUI firmware which is the modified version android. The modification is done the MIUI I.e Redmi company. Heating is a big issue with redmi 1s