Every time I think I should order GCMS, I get paranoid that it'll delay my application further and I back out.
My case is pretty untainted (young, single, applying alone, good job experience, high language scores, no crime, no traveling done at all in the last 20 years) except for the fact that I was denied PR in the US (as a dependent in my family's application) so I had to report it in the statutory questions. I attached all the information about that in my application and addressed it in my LOE.
My countries of birth, citizenship, and residence are all different so I also wonder if that threw them for a loop.