The sceenshot shows your line sync speed is 6688. In theory you could get download speeds of up to 5.5 Meg with that.
You don't say what the problems were with your other modem/router but I wonder if they could have lowered your profile to around 2 Meg, which would explain your slow speeds. If this is the case check the speeds should improve in 3 days.
Have you tried a speedtest in the early hours to rule out contention?