I have experimented with the QRS Pianomation system and anyone who
is interested who would care to check the MMD Archives will find my
technical findings.  I would _never_ remove a pneumatic player action
to install a solenoid action, simply because I do not want to destroy
an antique.

However, if a solenoid piano action is carefully constructed, with
properly programmed software and transcribed music, then "yes," these
systems can rival a reproducing piano.  Like most things modern,
these systems need refinement before that can happen.  "As installed"
won't quite cut it.

Computers lack the charm of a moving paper roll.  Conversely, electronic
media is inexpensive, and easily stored as compared to paper rolls.
Both have merits. Electronic circuits are compact, and dependable.
Pneumatic stacks tend to be cumbersome and heavy, however they have far
more power than solenoids.

So take your pick -- it's all in how much time you are willing to spend
on the instrument.

Andy Taylor