Got a Netduma R2 a little over a week ago replacing a Netgear XR450 that I had to RMA back to Netgear because the flash memory would not save the settings every time the power on the router was reset. As for the R2, I really like the DumaOS 3.0 over the 2.0. The new added features such as the polygon boxes, the heat pingmap, connection benchmark, and adblocker are nice. I have never had much success with QoS with any router I have owned but that has more to do with my ISP than anything as I have been with the same one for over the last 15 years now but the R2 seems to work much more accurately than the XR450. My ping rates have improved a little with R2 over the XR450 and it more accurately shows which devices are connected to the router than the XR450 ever did. The wifi connection at 5 Ghz is fine for my house with the R2 though it was a good bit stronger with the XR450. The 2.4 Ghz on the XR450 was super strong and had really good range but 2.4 Ghz wifi on the R2 is flat out weak. I connected my wife's Huawei phone as it does not support 5 Ghz to the 2.4 Ghz. From about 10 ft away, it was connected at 6 Mbps. 6! Fortunately that is the only device that needs the 2.4 Ghz as all my other devices all support 5 Ghz and/or are hard wired directly as my house is wired completely with Cat 6 to each room. So improving the 2.4 Ghz wifi on the R2 is something that obviously needs some work. The R2 does not have as many networking options as Netgear routers but for most people it will work just fine. The only other complaint i have against the R2 is the adblocker. When its on, Chrome on Android tablets almost comes to a halt. Safari on the Ipads isnt much better.
Since 2007, i started with a D-link DGL-4500, moved onto a Netgear Nighthawk R7000 in 2013, then last year moved to the Netgear Nighthawk XR450 and in less than year have moved to the R2 because of the hardware failure on the XR450. I really hope the Netduma R2 is a keeper for the next 5 years.