Originally Posted by roknroll

There's a deadline both promotions of Sept 30.

If this is for travel in the near future, the best option would be the 50% and 25k MQM promotion since you likely won't be able to capitalize on using the rebated points. If you have a longer time horizon, you could do the 40% rebate deal for a quick 100k miles, then wait until Delta does another 50% transfer bonus .