DumaOS hasn't had many updates to be honest. Overall the XR500 has been good and I like it. I've since upgraded to the XR700 and it's quad-core process seems to be snappier for navigation in DumaOS and allows for Plex streaming. Other than that wired gaming performance is the exactly the same between the XR500 and XR700. The DumaOS build on the XR500 and XR700 is also exactly the same build as well.
I have no problems suggesting it for
a sub $275 router still. That said... WiFi 6 is coming fast and will be here next month when Intel rolls out new platforms. I might wait and see what Nighthawk comes out with for that. Wi-Fi 6, or 802.11ax is supposed to be 30% faster than Wi-Fi 5, with theoretical maximum transfer speeds up around 10 Gbps. Netgear has already launch a number of new routers, but none are in the XR gaming series.
Netgear Nighthawk AX12 Tri-Band AX11000 Wi-Fi 6 Router
Netgear Nighthawk AX12 AX6000 Wi-Fi 6 Router
Netgear Nighthawk AX8 AX6000 Wi-Fi 6 Router
Netgear Nighthawk AX4 AX3000 Wi-Fi 6 Router
Netgear Orbi Wi-Fi 6 Mesh Router