I am adding Airport Express N (1st gen N) to the bedroom upstairs to AEBS (4th gen) wifi network that is downstairs about 60 feet and 1 wall apart. AE being added for Airplay to speakers in the bedroom. I set AE to extend the network and got impression that internet is slower even though the signal strength went up from fair to excellent. What is the best way to quantify network performance and decide if extending network is beneficial? I am running AEBS in dual channel mode with 5ghz network named same as 2.4 ghz one hoping that AE will extend the 5 ghz band.