Finishing work on 3rd and 4th floor units is moving along very quickly, and if you look closely, you can see the quality of construction methods and materials.  Most units on those floors are completely framed-out with stairs installed.  Electrical and plumbing work is now in full swing.  Check out the sound breaker bars!  Effectively these isolate the sheetrock hung inside each unit from the framing system, greatly reducing the sound that will be transmitted from unit to unit.