The Mi A1 runs on Android One. I bought it in February 2017. It runs Android Pie now, with android 7.1 2 the performance was better. The camera shoots nice pictures. The materials are of high quality and it feels very well. For enthusiasts and gamers like me, the CPU and GPU aren't strong enough in some cases. Overall a nice smartphone but the old hardware is a limit sometimes.
The phone is feature rich and the camera quality is at par with higher-end brands but rejected the phone within 3 months of using since due to the high amount of radiation. I was getting aches on the jaws, and side of the head whenever I was making calls. Also, if I keep the phone in pocket, the body part beneath that used to get a pinching ache. To rule out and to keep the phone very badly, I kept the phone at different locations, but the same result. Finally, I threw the phone away and bought Micromax Infinity (SAR 0.29). Now I am totally relieved and have a piece of mind. Kept Mi A1 as my stand by camera. Worth nothing else. It is a dangerous phone.