Hmm, that is somewhat surprising. Is that because they're "performing editions"? And Stapled is easier to keep open than sewn?
Just the opposite, actually. In my experience, at least, a well-bound sewn edition (Henle, for example) lies much flatter on the music stand than these new Bärenreiter stapled editions (52 pages and 70 pages). Because each page is part of a double-page sheet folded in the centre, the natural tendency of the book is to close. The only way to get the book to stay open is to open it at the centre pages, fold it back, then turn to the pages you wish to read, and fold the volume back again before putting it on the music stand. This will, in very short order, weaken the centre pages and/or the cover at the staples, and soon centre pages will be falling out.
That said, the scholarship is quite remarkable; half of each of these volumes is dedicated (in German, English and French) to :
in the case of "Pour le Piano"
- genesis and publication history
- discussion of the work
- aesthetics and performance practie
- notes on the edition
- the sources
- translation of performance instruction
and, in the case of "Children's Corner"
- title and musical allusions
- aesthetics and performance practices
- editorial principles
- the sources
all very informative and worthwhile additions to the music.
that said, i agree that i can't think of any respectable edition that is more than a dozen pages and stapled.
My Peters edition of the Schubert Impromptus (76 pages) is stapled and, over the years of use - although it's been relegated to the shelf after I purchased the Henle for the above-mentioned reasons - the centre pages are still intact but the cover has separated from the staples.