That and, in my experience, easier to find. Seagate
shipped wads of them
for use in early AT's. I don't love them either (slow and hot), but I do
have several more of them than any other MFM drive besides the Micropolis 1325.
I have a bunch of them, I remove them from use if I get them and replace
with D540s or whatever. It's a before they fail action So I do have a few
that are actually good with few if any bad blocks.
Allison