Originally Posted by
Bear4Asian
On Delta (qualifying miles) MQMs accrued above your earned status threshold will continue to roll over to the next qualification year. United does NOT rollover excess miles.
The above is very important. To that I would add:
1. Delta allows Diamonds to waive the $12,500 (I think) MQD spend requirement on Delta tickets by instead spending $25,000 on ANYTHING with a Delta Amex Skymiles credit card. United has no credit card spend waiver for its 1K's (those with 100,000 mile status.)
2. Delta's operational performance is way better than United.