I think TFS is like the opposite of Metropolis.
Whereas you have Metropolis, and then those ideas got heavily expanded on in SFAM, with the 12SS, you have these four songs, and then you take the best ideas from them and wrap them up into one sweet song that kind of embodies all of them.
As such, I don't see the point of saying, "I'd rather just listen to all those other songs," because to me, that would be like saying, "Why listen to Metropolis, when you can listen to Scenes From A Memory and just enjoy those recurring themes and ideas that they took from Metropolis?" It's a different song, that has some recurring themes, and I think it's extremely enjoyable because of that.