You might want consider transfer the MR points into BA instead of DL, particularly if you have a need for short haul flights within the US (as BA is a distance based system): you can redeem BA miles to fly with AA on such occasions.

You other chase card is likely Chase Freedom card, for many its a great companion card with Chase Sapphire Preferred card. Both would earn Chase Ultimate Reward points and can be combined (into Sapphire Preferred) to transfer all such points into a variety of airline/hotel programs (to maximize travel redemption options).