Robert Heinlein wrote a book called "Stranger in a Strange Land".  In
it, one of the main characters kept repeating the phrase, "Tanstaafl".
Eventually it was explained that it stands for "There Ain't No Such
Thing As A Free Lunch".

I often think of that phrase even to today.  It really applies to piano
work, where what is done in one area of regulation affects the piano
in many others.  In the case increasing the downweight in keys so that
they move as the player plays, realize that the corresponding upweight
of the key will be decreased.  In other words, the keys won't go back
up quite as fast.  This may result in poor repetition, not good in any
piano, especially a player.

I suggest that anyone who is thinking of changing key weights find
a paper by Bill Spurlock called "Grand Action Touchweight".  Find it,
read it, and understand it.  Then decide whether you want to change
things.

By the way, why is there a lock rail under the keys?  People today love
to see the keys move.  Did they not in the 1920's?

Jeff Davis in Seattle, where the drought is proclaimed over.

 [ The piano dealer might explain, "It's to reduce wear on the keys."
 [ The piano designer might say it's to disconnect the keys from the
 [ piano action so that the player mechanism (which pushes directly on
 [ the sticker or the whippen) has less mass to move and less friction
 [ to overcome.  -- Robbie