I just recently upgraded my internet from Extreme 250 to the gigabit network with xfinity. Problem is my upload speed increased but my download speed did not. If I plug my MacBook directly into my Netgear cm1000 I get download speeds in the 700's but I am getting around 200 through my router. I am running the most current Asus firmware. Comcast tech support said it was a router issue and recommended I switch to a Netgear Nighthawk router. I find it hard to believe that the 5300 can't handle...
Asus AC5300 on Xfinity gigabit network
Asus AC5300 on Xfinity gigabit network