I played "Siege" through the campaign and still got the failure debriefing music. It's not that big a deal in the long run, it's just that it's kind of weird to get a generally upbeat debriefing while somber music plays in the background. I still get the 'success' music after beating "Siege" on the previous (non-FSCRP) version of STL.
Also concerning music, in this new version of STL, whenever I get the "success" music in debriefings it sounds like FS2's. In the previous version of STL it sounded more like FS1's debriefing music.
Just some minor issues and is still an awesome campaign.