You are correct sims. I am couples matching with someone who is doing pediatrics. Our rank list got quite extensive, because we want to ensure that we both match. After all of our options to match in the same city were exhausted, we began ranking places that were somewhat close to eachother (Philly/NYC, LA/SD, etc.). If you list every possible combination, then it does not mathematically hurt your chances to match. Having said that, I can still potentially match lower on my list than if I had not couples matched (if I would have matched at my #1 but she didn't, so we went further down the list).
I reported it on ERAS and it definitely came up in almost every interview. Just a nice subject to talk about. I was worried that it would really hurt my chances to match, but I think if anything it has only helped (if at all). I even think I got one interview solely because of it. She interviewed at a program in November, and they liked her a lot and made a phone call to the ortho department and sure enough I got an interview. It is not as terrifying an ordeal as I had originally thought. Might be different if she was also applying to a competitive field. If I don't match, however, you can disregard everything I've just written.