Having gone through the Steinway showrooms in Hamburg and New York, spending time on all the Model D's, I would like to offer the following.
Firstly in New York. First a room of several D's. Then two D's that were going straight to Carnegie Hall. Then I was led to the basement (where horowitz played). Asking "are there any better ones", was led to an upstairs room with just two D's, one of which was very beautiful. Still asking for another piano, I was led to the foyer, with the Most Beautiful Piano I have ever played.
Hamburg: Similar situation, different accent. In both Steinway Halls there was a huge range of D's to suit many tastes, and one or two which I think anyone would say were in a class of their own.
This is why I think its hard to compare the two based on instruments in one's home city, given the original variance in the pianos as well as the fact that a piano is also a measure of the Piano Technician and the Acoustics.
Ive played a line-up of concert grands in the Paris "Salon de Musique" including Steinway, Yamaha, Kawai, Fazioli, and smaller US and Euro factories. However, same situation... I think one would need to tour the factories to find a piano to suit one's personality.
If choosing a piano for myself, I would hedge my bets and buy a ticket to NY, and search the factory there.
Having said that, when playing a concert in an unknown hall, I would rather know that a Hamburg D was there!