Yes i have ran a speedtest with the sliders at 100%. No difference. I even rebooted the R1 to confirm the settings took and same result
Are you on the latest firmware version (1.03.6)? It will be worth upgrading if you aren't. I'd try a hard reset (unplug the Modem and Netduma, wait 5 minutes, plug in the Modem, wait another minute then plug in the Netduma. Wait for it to fully boot up before another speed test).
Also ensure you're using a trustworthy site like Speedtest.net, and you've got Share Excess enabled and Anti-Flood at 100/100. Also try removing your PC from Hyper Traffic if it's in there.