Am I missing something or would it make more sense to swap the platter than the heads on this drive? It seems to have a lazy head, alternating between reading great and reading horrifically slowly but with no errors, about every quarter million sectors. Imaging head by head gave me a perfect read of one surface, with the other so slow that it will probably take over a month.
The datasheet I just grabbed shows only a single platter. Just for shits, I just tore apart a semi-broken (recovered) Z7K320-320, and found that the platter can be removed and reinstalled repeatedly (did it four times) and the drive still works. To top it off, I did this at my desk with some incredibly basic hand tools because I haven't finished pulling my cleanroom gear out of mothballs yet!

I haven't even touched the physical side of a hard drive project in a while and this was still insanely easy.
Anyone want to give me some reasons I would rather swap the heads if a media swap is so much less of an apparent headache? This seems kind of like the old Maxtor N40P, which only used the bottom platter surface anyway, and a monkey could swap the platter in five minutes.