The ideal reproducing piano -- this is a difficult question to answer.
I have had several reproducing pianos over the years.  When you mention
grands, I think the Ampico grand is much easier to service than a
Duo-Art grand, especially if one has to remove the piano action.  The
Duo-Art and Ampico uprights do not present these differences.

Personally I like the model A Ampico for it's ease of regulation in the
expression system.  If you ever had to remove a Duo-Art grand piano
action, you would appreciate the weird look of the Ampico drawer under
the keyboard.

Oddly, over the years I have encountered only a very few Welte
reproducing pianos.  I understand the Welte reproducers are very fussy
to regulate, and I do not know much about them.

Bruce Clark