Aside from the flash drives, I sprang for the entire, Page mastered, Led Zeppelin collection.
I've only heard the first disk, but I am surprised at the quality. I know that the early CD releases, (pre- Japanese re-mastering) used compressed second generation tapes to digitize. The rumor is that the original rough-mixed multi-track masters were used to create this set. I can tell you for sure that the tracks I have heard have a different sound than any of my other CD versions.
The thing that I notice right away is that that Bonham kick sounds better than ever on any CD ( almost analog!) and Page's old feud with JPJ has apparently been set aside in favor of re-creating the old ZEP for the fans! The bass kick ass, TOO, in other words. Clean, deep and up-front.
I hear none of the really trashy over- compressed digi-noise which ruined ALL the previous CDs. There is actually some dynamics to be felt.
(remember, when these came out on LP, even the average person's analog rig was capable of far superior fidelity and subtle nuances, compared to the garbage that ninety percent of the public listen through these days.)
I can't wait to get a chance to hear the rest of this collection with my "good stuff."