This weekend I went on my mileage run to Lima, Peru, thereby ensuring I'll be Platinum Medallion next year for (probably) the last time. If you follow that link you'll see my airtight logic that by using my (non-mileage-earning) Skybonus award ticket to fly to Chicago this coming weekend, I could use the money I saved to fly to Peru, earning 3 times as many Medallion Qualifying Miles and securing Platinum Medallion status with Delta.
Platinum or Diamond Medallion status is almost essential for securing low-level award tickets, both domestically and internationally. I regularly use the free award rebooking benefit to rebook legs from "medium" to "low" level (now called "standard" and "saver").
While that's all well and good, thanks to the recent Skymiles devaluation, Alaska Mileage Plan miles are so much more valuable than Delta miles (even for award tickets on Delta flights) that that's where I'll be focusing in the future.
All that being said, this mileage run was pretty horrible. While I was seated in Economy Plus on both my international flights and the one domestic flight on which I wasn't upgraded to First, the Atlanta-Lima route was being operated by an extremely old 767-300ER. One of the lavatory doors would not latch so when it was unoccupied the door was literally swinging open and closed with the motion of the plane (right at my seat, 19B). As I walked through BusinessFirst (no OpUp for me, unfortunately) I saw a personal video device Scotch-taped in place.
On the other hand, the service was attentive and the food was perfectly edible in Economy.
The most stressful part of the run was the unwillingness of the staff in the Atlanta airport to print out my return boarding passes. It ended up not being a problem since I had them printed at the gate in Lima. There is absolutely no conceivable reason for this restriction, but I couldn't find anyone in any Sky Club or at the customer service counters who was willing to print out my boarding passes – even though I could access them on my own computer, and was already checked in for my return flight. The Delta Sky Clubs in Atlanta also happen to be in a "transitional period" so their business centers do not have the ability to print documents. All in all it was an absurd set of circumstances for what is otherwise my favorite domestic airline.
In any case, if I ever feel the need to go on a mileage run again, I'll make sure it's short, domestic hops.