My xfinity speed is 100mbps. I cannot get more than approx 70mbps on 2.4GHz sitting right next to the MODEM where as with 5GHz I get the full speed. According to the specs at 2.4GHz the MODEM can go as high as 384mbps. Why? Also, is 5GHz more susceptible to signal loss through walls? I see much lower speed in my living room which is downstairs and about 25 feet straight line away through three walls.