Amex credit of $400 and travel voucher of $300 (this year's Platinum choices) did not make sense as a pair. I presume everyone took the credit and used it on travel. I cannot think of any extra benefit one received from taking the lower dollar value travel voucher. In fact, a higher Amex credit is worse for Delta and Amex since the purchaser of travel gets Skymiles twice (credited purchase) in addition to any multiplier for purchasing Delta travel on the Amex.

I believe the changes to $250 for the Amex credit and $350 for the travel voucher are meant to correct this and align the choices back to soemthing that makes rational sense.