It is 2,931,712 bytes (2880 KB) in MS-DOS. NeXTstep only shows "2880k". (I don't know of a lower-level utility that shows actual capacity in NeXT.)
Essentially exactly double the formatted capacity of a conventional 1.4 MB "HD" floppy disk.
The big problem is that it wasn't enough more than 1.4 MB to be worth the extra cost. By that point you had files that either fit on an HD floppy just fine, or needed far more than the ED disk gave you.
And the Zip drive and Magneto-Optical drives, and LS-120 drive all came out just a couple years later, before ED disks had gotten any more foot hold than IBM and NeXT, effectively killing it as a "new standard". (Although to this day, any motherboard that has a floppy port is nearly guaranteed to support 2.88 MB drives. Just as most server motherboards with an IDE port support LS-120 drives as a boot device.)
Essentially exactly double the formatted capacity of a conventional 1.4 MB "HD" floppy disk.
The big problem is that it wasn't enough more than 1.4 MB to be worth the extra cost. By that point you had files that either fit on an HD floppy just fine, or needed far more than the ED disk gave you.
And the Zip drive and Magneto-Optical drives, and LS-120 drive all came out just a couple years later, before ED disks had gotten any more foot hold than IBM and NeXT, effectively killing it as a "new standard". (Although to this day, any motherboard that has a floppy port is nearly guaranteed to support 2.88 MB drives. Just as most server motherboards with an IDE port support LS-120 drives as a boot device.)