Latency in IPv4 vs. IPv6 – Understanding the difference [pdf]
ripe70.ripe.net
ripe70.ripe.net
Let me also point out these other two very interesting talks from the same session:
1] A clever mindset from Geoff Huston (APNIC) to target IPv6 expansion: try to address rich people first! https://ripe70.ripe.net/archives/video/118/
2] A surprising statistic from RIPE itself: "The R&D team discovered that more than 400 LIRs stopped announcing their IPv6 prefixes in the last 12 months". https://ripe70.ripe.net/archives/video/122/
I'd imagine that IPv6 users would be people with better internet connection and that everybody in DS(hel)L country would be stuck with the short end of the stcik in every sense.