I just flashed build 21 and it has a bug with quicksettings.. when you try to swipe to see them or you press on the upper-right corner it takes like 5 to 10 seconds to show them... I did of course a clean installation.. I'll try redownloading and reflashing and I'll report again..
edit: I think it has to do with SystemUI... The locksreen takes also the same time to be unlock and it takes the same time to wake up the phone! :/
Edit2: Seem to be the same bugs are in build 20 I haven't flashed it before, but i just did and I have the same bugs :/
Previous phones: Xperia X10, Xperia Arc S, Xperia S
Current phone: Xperia SP
Rom: 4.4.4 Carbon