Enable smart roam is applied to the WLAN level, not AP level, and thus once enabled on the master, it would be applied to all member APs broadcasting this SSID.
This is my home setup on top of enabling Smart Roam with parameter 3 as well as enable ofdm-only. Every network is different and also dependant on your end user devices support, you can do fine tuning from all the configuration changes you can make from the WebUI and the CLI.
Thanks Tony. I am doing this in Unleashed using CLI.
What commands in CLI can I use to enable band, load balancing as well as Fast BSS? or are there other settings to play with. I have 4 inside AP's R610 and one external T710.