Another Netgear C7800 saga.

I had been on the Gigabit Plan, fat, dumb and happy. Then, last month, I got notified that  my speed has been increased "from 1 Gbps to up to 1.2 Gbps." Cool. So I waited. Then it happened (Wait for it...). My speed degraded by more than 10%. Where I was at 980+Mbps I am now at around 800Mbps. Long story short, they've thrown countless "technicians" at it, some of whom blatantly lied to me about the cause of the problem, all of them blindly repeating what the other had done multiple times because they don't review the service record. There've been two "technicians" here at the house in as many days with a third coming out tomorrow. I'd like to think "the Office of Tom Karinshak" is watching this topic since I got an apologetic email from there.

Here's the question: Is there anyone with a C7800 successfully getting "up to 1200Mbps?" If so. what's the secret? Don't get me wrong. 800Mbps isn't bad. But it ain't what I'm paying for and it's not what it was.