I think another factor in comparing an American-made model 'OR'
Steinway to a European-made 'OR' should also consider the difference
in the two pianos.  An American-made Steinway Duo-Art 'OR' made after
approximately 1923 is actually a model 'L' Steinway and not a model
'O'.  Generally, a Duo-Art Steinway made in the USA that does not
have a Tempomatic knob that turns is a model 'L'.  Some say the 'L'
has a more aggressive sound with a slightly larger soundboard.

As for voicing, I agree the piano on YouTube sounded as if the hammers
were hard compared to the 'O' that it was compared.  Some of the best
technicians are now using GC strings in the bass and Ronsen or Isaac
hammers.  Each tech has their favorites.

Don Teach
Shreveport, Louisiana