I have several examples of both Seeburg KT and Nelson-Wiggen
instruments (17 Seeburg machines, of which seven are KT style machines,
and three Nelson-Wiggen machines).  The KT xylophone model can play
with as much expression as the Nelson-Wiggen.

It would be unfair to say that the Nelson-Wiggen outplays a Seeburg.
They do not sound the same.  I personally prefer the Seeburg KT with
the single-stroke xylophone over the Nelson-Wiggen.  The KT regulates
the loud and soft of the xylophone with the vacuum supply, and the
Nelson-Wiggen regulates by moving the beaters closer to the bars.
The expressive capabilities of the Seeburg depend on the technician
that restored the machine.

The Seeburg KT Special verses the Nelson-Wiggen Style 6 could also be
debated for hours on end.  Both companies made a great product and each
should be judged on its own merits.  By the way, it was Oscar Nelson
and Peter Wiggen that originally designed many of the early Seeburg
models.

Don Teach