I've never chatted in this thread (I'm a CASA owner) but have 2 cents to say about sound proofing. There are definitely concrete walls between units in highrise condos. I think this issue really arises in towers with curtain walls of glass. As I monitored the progress of CASA, I noted that very thick concrete wall exist between units, extending to about 6 inches from the windows. I have no idea what they stick in that space, but I would bet that's where most of the sound comes through. I don't take possession of my unit in CASA until Feb, but I am dreading this issue. My existing condo is dead quiet.