You're using the "AMENDED credit". Technically you do not amend a return. You claim a credit on the current year's return (the year you make the repayments). Effectively, that will give you the same result as amending. The only way to know which is better is to do the calculations both ways and compare. But. a general rule is if you are in a higher tax bracket this year, than last year; the deduction is better. That assumes, you normally use itemized deductions and not the standard deduction.
