How about mileage redemptions?
Delta has been using married segment availability on awards since November 2014. You might be frustrated getting from AUS to an international gateway. (Unless you were just thinking Aeromexico!) Delta does have 20+ carriers available for booking online in contrast with AA's eight, so in that regard award bookings are easier.
Not speaking to the specifics of your destinations, Delta will get you more AVOD, more 2Ku satellite wifi, fewer CR2/E145 single-class planes. You'll find better on-time performance, fewer cancellations, and quicker and more reliable baggage handling.
I would look at the networks very carefully for one's own flying patterns. Delta has 8x to ATL tomorrow while AA has 11x to DFW; if you're headed west Delta can't match AA.