Did you do any tweaks to get that A+ grade?
I did disable quite a few things in the advanced properties of the adapter. I changed one setting then did the bufferbloat test to see if it made any difference.
The majority of the settings I changed were related to power saving/green ethernet/EEE/disabling flow/disabling offload.
Some of them didn't make much of a difference to the test results but were settings that were recommended on quite a few optimisation guides.