Mr.
Advantages: This is an excellent, perfectly built phone with a brilliant 5.5'' display, a fast processor, all necessary bands (e.g. for Germany), a useful OS (MIUI 8.1) and a very strong battery (4100 mAh, for me the most important feature). You will rarely find another phone with these specs in this price range. I am extremely satisfied.
Limitations: After 3 months, I still haven't found any... The only thing you have to be aware of: You can't operate a 5.5'' display with one hand (however, if you have to, you can reduce the surface to 5' temporarily, so it is not a real problem...).