So I ran some tests, 10 min ping plotter testes 2.5sec intervals.
First up with have an old WNDR3400v2 Netgear modem/ no qos on, just standard configuration, I ping plotted twitter, then google.
Below is the first test with the WNDR3400v2 on twitter
Then we have the same router, testing google.com
Now we have the XR500 doing the same test, with no Qos turned on / no antibuffer.
then we test google with the xr500
and here we have the xr500 with qos to 70/70, bufferbloat set to always
top graph was original test to google, with out, and bottom is with ^^^^^^