Build 4 is stable and really faster than previous builds but still some lags, I found a soultion for the lags, do the following steps,
1) Backup your services.jar from /system/framework/servies.jar
2) Paste the attached services.jar to /system/framework/services.jar using root explorer.
3) Change Permission to rw-rw-rw
3) Restart the phone.
Don't Panic it take some time to align apps to new services.jar your miui is go fly now.
User Memory Booster for better more performance.
@Ruben try to include in your next build,
And Ruben I can do only 50% supercharger with this OOM Priority Charger,
I need your help to do 100%
Original Thread is
(Thanks to eppelinrox)
Hit Thanks if helped
Note: This will work for Build4 only