I´m too 6'1'' - this seems to be the length of the AB seat - from head to toe. So, you might miss 1 or 2 inches on the AB seat for a bit more comfort, however I would prefer the AB-product to the old seats in the US 762 at any time. On the other hand, when I compare HPN with JFK, HPN is probably much more comfortable for you to arrive.

About lounges:
DUS: AB has an own lounge in DUS, however nothing to write home about.

TXL: AB contracts with the AF lounge, as OW Emerald or Sapphire you can alternatively use also the BA lounge one level down. I like both lounges even a bit better then the lounge in DUS.

ZRH: There is a OW lounge in the main terminal between A, where the VIE-flight most likely will arrive and B (however US departs from the satellite Terminal E). The lounge is in my opinion slightly better then the DUS/TXL lounges, also ZRH airport is very nice (and my current home airport)

VIE (my former home airport): AB/HG contracts with the Jet Lounge - they have great Do&Co hot dishes and soups there, or breakfast when you take the morning flight - out of the 4 mentioned lounges, this is my favorite.