I just bought the white one.looks very sleek indeed.
It looks superb.but God, wish I had the black one.
The screen is beast, I also use Samsung Note 4 with the Super AMOLED screen that I love so much, and Mi4s screen is not disappointing at all
I think the glossy back cover of the white one will be worn off with times, so to use a protector is very recommended
Yes, too bad its only single sim phone, since I have 3 sim cards, one of them is already on my Note 4 and only another one can go into my Mi4.
If you fancy a phone for it looks, Mi4 is worth a try. In performance term, I think its equal with, lets say, Iphone 5s.
The charging is quite fast, but I dont know about the overheat issue yet, since Im not a heavy user anyway.