I've just replaced my BT HomeHub with a combination of a HG612 (flashed with B030SP08 firware and QOS disabled)) and a shiny new ASUS RT-AX58U (running Asuswrt-Merlin 384.16).
I'm getting poor bufferbloat performance (C rating (30ms idle, 60-130ms downloading, 30-210ms when uploading) on dslreports, and nothing I change on the AX58U seems to affect that bufferbloat score. I've tried altering the bandwidth between 95% and 50% of my max line speed (max is 40Mb down, 13 up), and it just stays the same!
Could the issue be down to limitations with the HG612? If so, what would a current recommendation be for a replacement? Note - I would only need a replacement to act as the modem as the AX58u is only 2 days old!!