Upgraded to 4.4.2 yesterday, had problems like others here:
- dropped calls when receiver picks up (Maxis mobile to Maxis mobile)
- dropped calls after 1-2 minutes (Maxis mobile to landline)
- Bluetooth service crashes. Can pair but crashes when connecting

Wasted one day wiping, flashing, testing, downgrading and setting everything up again. Not much benefit from the brief time with 4.4.2. In normal use, phone seems no faster.

I suggest not upgrading until the next version is released...