It's an apartment, if I didn't duplicate floors/keep the floors the same, then it would be one of two things:
1) Completely handicapped, each floor being different? Seriously, that would look messed up.
2) Take me forever. If I made each floor unique, room wise, as well as not use a duplicator wand, it would have taken forever. Sure it would be awesome, but I'd like to see you do 68 custom rooms.