#1 So here's my setup: Main airport express downstairs in living room with modem. Second airport express extending the existing coverage upstairs in the office. Can I connect a printer via usb to the second upstairs airport express and make it a wireless printer, or does it need to be connected to the main airport express downstairs? Also, is it better to "extend network" vs. "join network"? What do I lose if I "extend the network"? Also, am I correct in thinking that I can use BOTH airport express units for wireless airplay?