I think every landlord is probably different, but when I asked a former landlord a while back what he looks at when he does his credit pull, he said he's not looking at the credit score, but rather for bad accounts that might suggest that a person is a leasing risk. So if your credit report doesn't have any recent delinquent accounts or active collections, then you're probably fine.
The question of credit card balances didn't come up when I talked to him, so I don't know if high balances is necessarily a red flag to landlords. But conceivably it could be a factor.
