Both are controversial, because they have little to do with Bartok.
Bartok left a pile of chaotic sketches, too chaotic to speak of any
"reconstruction".  Each can be better regarded as a new work, based on
Bartok's sketches.  It does not represent Bartok's music, quite simply.
For the same reasons, neither does the Bartok Jr/Neubauer work.

I like Serly's work (I haven't heard the other (is it recorded?).  But
it's not Bartok.  It may be Serly's best work, but not Bartok's.

-Margaret Mikulska