I made a blog entry earlier about The Menzingers Demo reel for their most recent album On The Impossible Past and I have honestly been obsessed with their original demo for "Sun Hotel":
Sun Hotel (Demo)
The lyrics and structure are completely different from the album version:
Sun Hotel (Album Version)
I'm not necessarily saying it is better, I just feel it's completely different subject matter. The demo version feels more personal and heartfelt (It IS acoustic, after all). Perhaps the band felt it was too personal to put on the record? Or maybe the original version of the song didn't fit in with the concept for the album.
If anyone ever catches those guys on tour, I'd love to get an answer.