I tested various roms within the last few days - AOSP 5.1, CM 12.1, MIUI V5 4.12.5 (4.3), MIUI V6 5.3.27 (4.4), IUNI V3 (4.4), TencentOS (4.4), etc.
I came to the conclusion the bugs diminishing the essential functionality as we witness in Android L-based MIUI V6/V7 roms are possibly the...