For many years I have been using the OpenDNS servers, until it was made known that Cisco took them over, just like Oracle took over MySQL, now anyone that stays current on security news, doesn’t trust any of them. MySQL and OpenOffice have been replaced with MariaDB and LibreOffice, open source software–there is a reason for everything. I’m currently pointing my routers to primary DNS 9.9.9.9 and secondary DNS 208.67.222.222 however, I’m thinking of dropping the secondary completely and just running with the Quad9.
If you’re interested in this nonsense, you might also interested in running some benchmarks on DNS servers. For this I suggest you grab a copy of an awesome program written by Steve Gibson back in 2010 called DNS Benchmark. By right clicking on the title bar you will find more options than you ‘ll know what to do with. The program is Freeware and is crystal clear clean of any trickery like advertising and spyware….. DNS Benchmark can be found here.
For more info on Quad9 and what it does for you, you can find that info here.
Have a marvelous day!
heinz

2019-11-08
Well, some time has passed since the 9.9.9.9 guys spun up; now there’s the Cloud Flair kids with 1.1.1.1
Will do a test/review on that DNS server. Also, to mention, here is an awesome DNS speed tool by GRC called DNS Benchmark, you can get it here. https://www.grc.com/dns/benchmark.htm
–heinz