I greatly favor a heavier keyboard touch on any Steinway Duo-Art Grand.
Here's why.  The Duo-Art is a single-valve system.  As such, the entire
piano action and the pneumatic player must be fully integrated and
precisely regulated to work together as a musical couple.  Double-valve
systems are far more tolerant of sloppy regulation.

Once the total regulation is complete, the final step is adjusting the
"zero setting."  It will be plain that with a heavier touch, a slightly
higher zero setting is necessary.  This assures a more positive valve
action with better repetition at the softest playing levels.

All the Steinway upright pianolas I'm familiar with have keys that are
heavily weighted in front.  When playing a roll, the keys drop
noticeably faster; but when shut off, repetition is better.  When
making the zero setting on any upright Duo-Art, the keys should be
locked so they won't move.  Incidentally, it's also better to lock them
when playing a roll.

Jeffrey R. Wood