Hi, I have an Airport Extreme (simultaneous dual-band), and also a current-gen airport express used to extend the network and plugged into my av receiver for airplay. I'd like to add two more wireless routers to my home to extend the network, to improve reception in my basement and garage. 2 questions, 1. If i add two older airport expresses (like a/b/g), will they slow down the rest of my network capabilities? or will access at the other points remain as fast as it is currently? Will the slower hardware throttle back ALL of the hardware? 2. Can i add cheaper third party routers to the mix, or do they have to be Airports?