Originally Posted by Haleyb

Another thing to take into consideration is the credit lines. You don't want to transfer a balance that will put you over 50% on any one card, I'd keep it below 25% myself but don't know what the best number might be.

How this relates to points, don't tie up your best point earning card!

The way they apply payments to a BT means you pretty much need to ice the card while you have the BT balance on it.