It's been so long, and of course, back in 1980 all I had was my Apple disk II drives so my memory might be fading about how good they were compared to others. I mean, who had 2 or more different computer systems with disk drives back then? However, it seems to me that the venerable Disk II leaves just a little wanting.
My drives will only format about 50% of the brand new, still sealed in the box Memorex SSDD floppies that I got. Neither drive is better than the other and both are very gently used, clean as a whistle and test out just fine with any diagnostics I run on them. Here's the rub, my similar vintage Tandy COCO (uses the same drives as the TRS-80 Model 1 and formats them at a similar capacity to the Apple) has no problem formatting and using the ones the Apple can't cope with. To the COCO they are all just fine and dandy.
Now, I don't doubt Woz for a minute, but is it possible he left a little something on the drawing board when he designed the Disk II system? If so, is there a way to increase their performance?