In such a case, where you are still pushing the case for IPv4, how do you envisage things will look on your side when everybody else you want to talk to is either on IPv6, or frantically getting it turned up? Do you reckon anyone will have time to help you troubleshoot patchy (for example) IPv4 connectivity when all the focus is on IPv6?
I've put that concern on my calendar for sometime around 2025. People have been saying switch to IPv6 now Now NOW for about a decade, and you can only cry wolf so many times. My servers do IPv6 through a tunnel from HE (thanks!) where the performance is only somewhat worse than the native v4, and my home cable has v6 that mostly works, but the key term there is mostly. (The ISP had a fairly bad internal routing bug which apparently nobody noticed until I tracked down why my v6 connectivity was flaky, and I happened to know some senior people at the ISP who could understand what I was telling them about their internal routers.) We've just barely started to move from the era of free IPv4 to the one where you have to buy it, and from everyhing I see, there is vast amounts of space that will be available once people realize they can get real money for it. The prices cited a couple of messages back seem to be in the ballpark. It will be a long time before the price of v4 rises high enough to make it worth the risk of going v6 only. R's, John