While I wouldn't call them rubbish, I do find the Companion Audio to be very disappointing. Like OP said, and I have said similar many times in the last thirteen months, most of the tracks are just the masters we know with a slightly different mix (tambourine higher), fewer overdubs, or a missing vocal.
When these remasters were announced, and it was said we would get unreleased material, I was expecting alternative takes, demos/song sketches, outtakes... something akin to The Beatles Anthology. I agree with The Old Hermit, I wish Page hadn't been so hardliner on not released already bootlegged material. I would have been totally ok with material that has been bootlegged if it were clean, clear, and coming from master or early-generation tapes. It angers me when Page says the vaults are empty and there's nothing left. We Zep heads know there's more!
Page was getting there with the alternate SIBLY, In The Light (both alt. versions), Bring It on Home, and India recordings, but he really dropped the ball. Not a good way to close the Zeppelin vaults.