A good start but doesn't examine one case that I'd like more data on: most deep packet inspection boxes can't handle IPv6 so the packets pass right on through, unimpeded. I've heard it's provides a speedup and it seems totally plausible: without some ISP's marketing panopticon or (shudder) JS injection, it seems like your connection should be much faster.
Someone can correct me if I'm wrong, but the deep packet inspection systems I've seen to date are passive. They take a copy of the bitstream on the wire and don't impede that stream in the slightest.
I guess I was simplifying too much. I meant generic middleboxes that do everything from read-only DPI, to transparent caching, to content injection, etc. They're out there and they're annoying.
I'm curious to know whether there's a difference if you break it down into mobile vs desktop users.
who cares much about cross continent requests when you care about performance? if you're on that situation, ipv4 v 6 is moot.
It is time for IPv8, which will be upgrade for IPv4, not a complete replacement.