I have a Discover card with a balance of $850/$8000 with a 19% APR. Of all my cards it is the only one with a balance. I just opened a new Discover card with $1,500 CL that has 0% APR for 18 months (3% charge for balance transfers). I also have an AMEX card that I recently opened with a $6000 CL and 0% APR for 18 months (3% charge for balance transfers). I know that AMEX doesn't like you holding balances. Should I balance transfer and which card would be better?