Transitioning to an all MAC family. I bought the new Airport Extreme router and got it set up. The new one has two separate networks, one for 2.4 GHz and the other for 5 GHz. My first question is the iMac, MacBook Air and IPAD 2 can all access the 5 GHz network. On the iPhone 4, that network doesn't show up so I assume it isn't compatible and can only connect to the 2.4 GHz network. Am I still able to access files between the 2.4 GHz and 5.0 GHz network since they are on the same router? My second question, where the iMac is located I get 2-3 bars of signs strength on the 5 GHz and full strength on the 2.4 GHz. Am I better on the faster network with the weaker signal or do I want to go for the stronger signal? Finally, I plan to add an external drive to the router in the near future just to serve the purpose of time machine backup for all my computers. Will I notice a big different between the 2.4 GHz and 5.0 GHz networks for the time it takes to backup or are the write speeds on an external through the router slow enough that wither network will work? Thanks!