Talking with RTI yesterday, they say the high gain adds about 30 to 40 feet to the T2 range but does very little to correct for a noisy environment that is limiting RF range. The CM-232 is used to interface with RS232 port equipped components. I don't know what extra cable is, that they are talking about. They just started shipping to their now limited distributor network, I will have them on my site at competitive prices when they arrive.
Bill
www.homeautomationnet.com