Just reporting that I upgraded my WNDRMACv2 and WNDR3700v1 units to version 1.10.0 from 1.9.x from September 18, 2017. Did not preserve the settings. On the WNDRMACv2, I tested DDNS, OpenVPN, AdBlock Plugin, USB Camera, QOS w/ACC and WIFI (Both 2.4Ghz and 5Ghz). All seems to be functioning great!. On the WNDR3700v1, I tested USB Printing, it functions great as well. I also have 2 vlans (guest network completely segragated from regular network with internet only access) and vlan tagging setup between these 2 units and it is functioning great as well.
The only strange anomaly is that the WNDRMACv2 seems to always report an idle of around 0.72.
I've tried turning off openvpn, AdBlock plugin, QOS w/ACC, WIFI, and turning off Bandwidth monitoring through SSH and the idle usage never goes below 0.69. I've reflashed the firmware and it still shows the same usage even after a couple of factory defaulting. I experienced the same issue with the 1.9.x from September 18, 2017 as well. I don't experience any slow downs on the network, everything seems to be snappy with the web interface. When I SSH into the unit and do a top command, I see know excessive usage in memory or processor. Go figure.