I just discovered (and downloaded) a bootleg recording of the 1978 Chicago premiere of this work. Near as I can tell, no official recording exists and it hasn't been revived since its debut in Chicago and a few venues in Europe.
It's definitely a flawed piece, to put it charitably. The libretto is awful, and much of the music overlong and frankly pompous. However, there are some very interesting moments. Not surprisingly, Penderecki's evocation of Sin and Death are impressive and there are a few passages which carry some of the existential dread that permeates "Saint Luke Passion." I'm surprised that it's languished in such complete obscurity. While Penderecki managed to get an adagietto out of the music, he never came back to this one... and neither, near as I can tell, did anyone else.
I've also gathered the story behind the creation of Paradise Lost is an epic in itself.
Anybody know any more about this piece? All information is greatly appreciated.