I suggest you to install immediatly this ROM.
When i got this phone, I stayed one month on china stable, because I wanted to enjoy a phone with MIUI preinstalled as stock and, I thought, optimized as well.
Then a friend convinced me to switch to this rom, Xiaomi eu developer rom, and I was surprised like never before! Xiaomi eu's roms are based on official MIUI but they are smoother, faster, lighter and equipped with really userful and awesome mods!
Meanwhile official global has been released for my phone, but I prefer staying on Xiaomi eu because the difference is huge!