This is no guarantee or a perfect solution, but you can attempt to make your Internetz more responsive. I have only tried Google namebench OS X and no experience using GRC. I did this early 2012 after I built my Hackintosh and did not run Microsoft Windows at that time.
Here are the two tools:
GRC Domain Name Speed Benchmark
Here is the Tekzilla Video: (Starts around 7:50)
WARNING!! for Google namebench:
For privacy concerns, change your Query Data Source from your browser (Google Chrome) to maybe the 2,000 Websites (Alexa).
Otherwise, it will use your bookmarks for the benchmarking.
For countries that track / censor websites, maybe it is best to just have a browser with bookmarks with nothing but poker sites and run your test from there.
namebench recommended I change to Google DNS 188.8.131.52 since it was supposedly 300% faster than my old OpenDNS setting from my country.
I made the change on my tomato router.
The Internetz seemed more responsive after, but I took no measurements.
Results may vary.
A theory I have is if every Poker system in the world optimized/optimised their DNS to be more efficient, maybe it will help a little on the Lag side. Just a dumb theory.