I am currently evaluating a QRS Pianomation vorcetzer (trade name
"Playola") on a well regulated Yamaha C3 grand.  My wife tells me it
should be called an "on-cetzer" because it sits "on" the cheek blocks
of the piano rather than "sitting before it".

There's a bunch of experiments that I want to do with it regarding
how the MIDI files are interpreted, but I can make the following
observations:

    The relationship between the solenoid stroke and the key
    travel must be adjusted correctly.

    The minimum solenoid operating force must be adjusted (in
    software) for each note.  This requires a calibration box
    on the Pianomation system.

    Once adjusted, it plays quietly enough when my family is
    home, and loud enough when then are not   ;-)

    I'm having a lot of fun with it, and like the fact that I
    can take it with me when I visit friends.  In fact its
    has already visted Robbies upright pumper (!)  An interesting
    side note is that the minimum operating force was dramatically
    differrent for each solenoid on his piano compared to mine.
    Robbie's piano's action is much older and has widely varying
    friction from note to note.

    I believe that solenoid pianos with closed-loop solenoid
    velocity control will be required to achieve things
    like the very soft trills that Neil talks about.  Such
    closed-loop systems are expensive.  To my knowledge,
    only the Bosendorfer SE and Yamaha Disklavier Mk II (just
    released) have this capability.  Since most of us already
    own pianos and these systems are not "aftermarket", that
    leaves open-loop systems such as Pianomation and PianoDisc
    for the rest of us.  The vorcetzer packaging was a definite
    plus for me.

I hope to provide more information about how my testing goes in
a later, longer article.  In general, though, I'm having a lot
of fun with this unit.

Jody