I'm with you on this one. I wish more people (anybody?) had heard & lived with Iapetus for a while, but Motivation is, like Iapetus, a wholly unique record that has been virtually unheard.
As I type, I'm listening to Iapetus on headphones. I gotta say — this really is a great record. More than Motivation, I think, this is a band effort. While Caliman is clearly the leader on the session, the rhythm section has that feel (not muscially, but socially) of the great Hancock-Carter-Williams team. It's weird — tenor players working today would eat this up, I'd think. Meaning, I can't believe that this session hasn't seen a reissue anywhere. The record, though it bears traces of its recording year, has an unusually modern feel to it. This is to say that the music, almost note for note, might easily be heard in a hip club anywhere in the world today.
I think of Iapetus as the next step after Filles de Kilamanjaro that Miles himself never took...but a group of Bobby Hutcherson sidemen did, on an album that got a ***** review in DB (iirc) & then vanished w/o a trace.
There's really not anything else quite like it, and yes, it stands on its own merits as strong today as it did then. I think it qualifies as a stone classic.
Now that I think about it, so does Oliver Nelson's Black, Brown, & Beautiful on Flying Dutchman, the original one, not the later reissue compilation of the same name. That arguably is Nelson's true masterpiece, more so than Blues and the Abstract Truth. And it's never been reissued on CD, not even on compilations that I know of. But it is strong, strong music.