"Help I'm A Rock" was essentially a jam, and WOIIFTM was an album of songs with some nice inter-track additions.
"Billy The Mountain" as presented was a full length production number, one continuous piece with a linear narrative and unified thematic elements from start to finish. Nothing else quite like it, really. 200 Motels, maybe, but not really.
I have some bootleg that presents a version of Billy that is a condensed version, perhaps more than half the original length, and it just doesn't work. It's too glib, doesn't breathe, not enough time for things to really develop, simmer, whatever.
At the level of completeness that it got, it's good for more than jsut a giggle for me. It's got completeness. In long-form "rock", that's quite a rarity.