Ok, just got off the phone with Sin. She pronounced it 'Seen'. So Neil is the winner of the Xin pronounciation contest, lol.
What a beautiful sweet voice, and she sounded just as I imagined from our letters-very happy, playful, always laughing. We talked for about 45 minutes, she taught me a little chinese, and I helped her with her english pronunciations. Whatever small doubts I had before are gone now, going to halt all contacts with anyone else, although to be honest I've already pretty much done that, anyway.
I realize that at this point, it may or may not work out in the end, but I just want to say this. Cecily, our translator at the Wuhan agency, has done a great job. The personalty that came through in our letters is the personalty I just experienced on the phone. While it's obvious that some of the agencies aren't to be trusted, at this point I'd recommend Wuhan Oriental Love Consulting Company P509. I can't say what the rest of the translators there are like, but if Cecily is a good gauge they are excellent. And of course, it depends on how involved your lady is in the writing of the letters; Xin has told me she usually writes hers down and takes them to the agency. Maybe I just got incredibly lucky, but I am very satisfied with the money I've spent there.