Talkin Merz and box. These 6cd Slowdown boxes (stated date of recording) are pure gold:
Loop & Collage (84-87)
Strings & Percussion (86-88)
Tapestry of Noise (89-91)
Metallic (93-95)
Green & Orange (96-98)
While these consist almost entirely of alternative takes and mixes of the releases proper (exception being Loop & Collage which includes Crocidura Dsi Nezumi and Enclosure), I'd say in terms of overall sound flavor & texture there is unsurprisingly a great deal of overlap*. Merz kind of is a study in overlap, or self-plunderment. Merzbowelment. What's in a name you say. Merzbow unequivocally, and with due apologies to FdW, sounds likes Merzbow.
* with the releases proper and the Merzbox and the other Merzboxes**
** the 10cd Youth Inc sets, Merzphysics and Merzmorphosis, are possible exceptions, as far as repping more raw and untreated materials as I've
commented on in the dedicated merzthread.