https://www.potaroo.net/
From Conclusions:
"When considering the larger pool of all users, then these results indicate that some 0.01% of the Internet’s entire user population may encounter some DNS resolution issues when the KSK rolls.
The uncertainty levels in this measurement are ± 0.22% as measured by the noise component of the results. As this is far greater than the non-readiness measurement of 0.01% of users, then perhaps there are grounds to believe that the situation may be better than these figures would indicate, and the true level of non-readiness for the KSK roll is far smaller than the 0.01% of users that these results indicate.”
Regards, David
David A. Olive | Senior Vice President
Policy Development Support
ICANN | Internet Corporation for Assigned Names and Numbers
801 17th Street NW, Suite 400 | Washington, DC 20006