> But it isn't? I mean, yes, every machine that requires both v4 and v6 is more complicated than just v4, sure.
You don't need to do that. I've set up IPv6 only networks at conferences. If throw in a IPv6->IPv4 NAT (eg, tayga) the only machine that requires a dual stack is the router. We didn't have a single complaint about connectivity issues from over 500 delegates. Modern clients (phones, tablets, Mac's and so on) just slide seamlessly into an IPv6 environment without the user even being aware they are using IPv6.
I am pretty sure that if I put all of the servers that I am involved with behind NAT64, the complaints would be instant because tons of stuff would break, from services running on those servers not being reachable via IPv4 to software running on those machines not supporting IPv6.
You don't need to do that. I've set up IPv6 only networks at conferences. If throw in a IPv6->IPv4 NAT (eg, tayga) the only machine that requires a dual stack is the router. We didn't have a single complaint about connectivity issues from over 500 delegates. Modern clients (phones, tablets, Mac's and so on) just slide seamlessly into an IPv6 environment without the user even being aware they are using IPv6.