Ok they said that with the current setup one Antenna handle the incoming and outgoing 2.4ghz signal. With the pro version of the ST16 one Antenna handles the out going 2.4 ghz signal and one handles the incoming 2.4 signal. So that's what the Rep said. Funny thing is, then he started to say there was no difference in performance with the old antennas compared to the new ones. I couldn't help but laugh. Please when they change something its for a reason.