In the past I was always told by colleagues 184.108.40.206 appears to work faster and have to combine that with Google's public DNS*. Using 220.127.116.11 as primary and 18.104.22.168 as secondary. However, Google only provides 22.214.171.124 and 126.96.36.199, so who provides 188.8.131.52? And if true, why is 184.108.40.206 faster?
*Note: These IP addresses are used to dig domains and to determine if local DNS changes has propagated over all over the internet.