I figured that I should update this and provide my experience of same day turn in IST... it wasn't as easy as it was made out to be. YMMV.

The transfer desk *would not* issue my return boarding pass. I went to the transfer desk and met another FT'er on the same mileage run, so we collectively tried to convince them that what we were doing was indeed a transfer and indeed a normal thing to do. The gentleman called up to the Delta desk, and they agreed -- we were told we had to buy a visa, exit through customs, and recheck at the Delta desk upstairs. At least now I had a buddy (now I realize that this may have made us even more suspicious...at least he was a cool guy).

Customs was a breeze. I now have a $20 sticker in my passport as a memento.

When we got upstairs, we went to the security desk right before the Delta counter. Here's where the problems began.

A: "How long were you in Turkey?"
R: "About two hours."
A: "Business or pleasure?"
R: "Um, neither? On a mileage run."
A: "Mileage run?"
R: "It's where you fly for the sole purpose of getting miles."
A: "Why Istanbul?"

The questioning went on for a good 5 minutes. "How do you know each other? How long have you known each other? What do you do back in the states?" There were a lot of repeat questions, they couldn't believe that we met at the transfer desk, that there were three of us, the the security person claimed that he "had never seen anything like it." The security agent took our passports and walked over to another desk. A bunch of people gathered around, and they were discussing fairly intently and studying our passports. We waited for 10 minutes before we got our passports back.

At the Delta desk, the only Delta employee (I guess that's the station manager?) said that there were a total of three people doing the same thing on that day and that she's "never seen anything like it" and she "couldn't understand why anyone would want to do that."

We get our boarding passes, stress the importance of getting my status again this year, and go off through expedited security and into the club. The club was nice, and I loaded up on Efes, cheese, yoghurt soup, and free internet. There are clean and less-used bathrooms on the club level (on the other side of the escalators.) The food court also has some great food downstairs (with the exception of Popeye's Chicken... what the fark is that all about?)

We went to board our flight. After getting through the metal detector, the lady looked at our passports and sent us in for more screening. I guess our passports had been flagged.

We go to a security supervisor who now asks us another litany of questions. We walked up and, without looking at our passports, said: "You are the gentlemen from New York..." Our trip obviously had caused somewhat of a stir. "Where's your other friend?" He was referring to the third passenger, and apparently, they thought we knew each other and were all part of a nefarious plot. The questions continued for several minutes. We eventually had to sign a list saying we had been through additional security and had our bags dismantled, a "TSA resolution-style pat-down" and our shoes checked carefully. It was only then were we allowed to board the flight.

I'm dumbfounded that they haven't seen folks on a mileage run in IST and that our trip caused such a commotion.