I went to PB Tech and bought one of these (D-Link 890L router) today.
I then installed an ASUS PCE-AC68 PCI-E Wifi antenna in my desktop system, replacing a USB3 ASUS wifi adaptor.
I had been getting up to 300mbps on the USB3 adaptor, but I wanted more. The desktop and the wifi router have been about 10m apart, through two walls. On the HG659b router, the 5GHz connectivity was seriously marginal. 2.4GHz was much better. But still not enough.
Once the new gear was installed and running......I did get more. Here's a screen shot of my connection status.
I also tried a speedtest. I got double the usual throughput for the downlink, but I'm still stuck at 20mbps on the uplink....and I'm paying for 200/200.....so something isn't right there. I'm thinking a 526mbps connection should be able to do better than 20mbps on the return leg.
One thing that was a little disappointing is this router doesn't support PPPoA for direct Fibre connection. So it's plugged into my HG659b. But I've seen in the past how simplifying the job the primary modem router has to do can see it perform very well. Don't burden it with several clients and many different sources of traffic. Just feed it traffic through one port and let that traffic already know where it needs to go (the secondary router does the DNS for all clients).