[masterofnothing]

Interesting, because based on these statistics, IPv4 seems to be a better choice. Faster and stable. Curious, not sure if I would expect that.

[faxmachine]

I think that the main reason is exactly what the author mentioned on his conclusion:

"Perhaps the way IPv6 deals with additional headers in contrast to IPv4 may be influencing this difference. This stability is observed most evidently on sucuri.net and cloudflare.com. Interesting, as both domains deal with web security."