Krissy...a really good question, actually!
I know we all have put so much effort and time and thinking and worrying into this whole process...and yet I can't think of a soul that I have heard who's been denied either the spousal or the fiance visas! We've had some sent back, but they were trying to come under the wrong visa (or what was perceived as the wrong one). So, they got their stuff in order and tried again for the right visa...and got through.