Here someone who bought a Mi4 months ago, for $160 (Long story short, mostly impressed despite obvious things):
1) Increedible (just incredible) build quality.
2) Good software, fits the hardware much better than 90% Android devices. Old, "slow" phone, still gives smooth experience.
...both 1) and 2) still worse than iPhones. Any iPhone.
3) Had problems but always related to third party modifications of the software for usage in Europe.
4) They want to be Apple and do properly most of the job... but you understand that if they had to develop everything they just imitate (mostly steal), the phone would cost like an iPhone.
This is their first original move. I'm not saying it will affect Apple but just don't take it as irrelevant. Even if you don't like them, when you know what they can do and for what price, you're curious about their future.