> I'm seeing too many reviews online about shiny new buildings in and around DC with paper thin walls and crappy front doors that let you hear everything in other units.

FWIW, my building has a ton of reviews complaining about those things, but I've lived here for 7 years (in 3 different units) and haven't actually found this to be too much of a problem. (Folk in the hallway can definitely be heard too clearly, but from other units I haven't ever been disturbed.)

But maybe I've just been lucky -- I definitely understand not wanting to gamble on this!