Slowest-seeking floppy or hard drive ever made?

Hi guys, Does anyone know what the typical range of floppy and ST506/ST412 drive track-to-track seek rates is? I'm finding myself having to modify the seek logic in the DiscFerret to accommodate the Seagate ST-277R RLL drive, which requires that buffered-seek pulses be spaced between 8 and 200 microseconds apart. Any more than that and it assumes you're doing a 'slow' seek at 10ms per step. At the moment the DiscFerret's step rates are set up in 250us intervals, with an 8-bit divider register. Seek rates can be between 250 microseconds and 64 milliseconds in this configuration. Feeding the ST277R the 250us step pulses... really screws it up. The drive deasserts READY and SEEK-COMPLETE and seems to freeze up completely. Hardly unexpected... If I change the seek clock to 125us, I get a minimum of 125us and a maximum of 32ms using the same divider. Is 32ms likely to be enough for even the slowest drives? Out of curiosity, does anyone know what the slowest-seeking floppy drive or MFM/RLL hard drive ever made was, and what its track-to-track seek rate was? Thanks,