It's a great idea, they should've done that long time ago. Specifically where it makes sense, it maybe even a better idea to allow for a mix of office, and residential within one building, obviously with separate entrances. Apartments like that usually have bad floor plans, with windows in only one side of the apartment. Mostly works well for 2000 sqf apartments, where you want a walk-in closet the size of a bedroom, and efficient use of space is less important.