I agree and have had similar experiences as Chuck. All the Maxtor and Seagate MFM drives that I formatted RLL performed flawlessly for all the years I used them in that configuration.In my experience, if you've got one, it's worth trying an MFM drive and formatting it as RLL. I did that with numerous non-RLL-labeled drives and got very good results.
Picked up a clone that lost its HDD along the way.
Has a Seagate st11r card inside.
What drives that are somewhat findable would work with this?