Jason writes;
  Ethan, this hd ST251-1 is equally bad and it uses
stepper not voice
 coil.  Can see the stepper itself.  Also this hd have lot of
 reliablity problems and very touchy especially handling, very
 loud noisy. 
I sit corrected.  I had thought that the 28ms version used a voice coil
and the 40ms version used a stepper.  That is not the case.
As for noise, yes.  It's noisy by today's standards.  All of the old
drives were touchy WRT handling.  I didn't consider it more so than
any other 8 year old drive.
  Compared to ST251 series, ST351A/X series is pretty
sturdy and very
 low powered. But this ST351A/X is easiest to find than this
 Miniscribe XT ide 8051A is voice coil and that is all I know that is
 only one that does XT ide or AT.  
I have never run across the ST351A/X series.  I don't know how common they
were; I wasn't into PCs in 1989, just VAXen and Amigas.  They do, however,
use steppers (28ms).
-ethan