Just to share...just recently did balance transfer to Maybank from Citibank.
Fax all the docs to Maybank on 7th Sept. (Friday) afternoon, today 13th Sept (Thursday) call and checked with Maybank.
Balance transfer has already approved few days back and I can see the amount already paid to Citibank yesterday 12th Sept. (Wednesday)
So overall from my experience it took less than 1 week to do balance transfer with Maybank.