The only thing ipv6 has going for it is virtually unlimited addresses. It is much more difficult to set up securely. We use NAT in ipv4 to assign local network addresses and have one public IP because of scarcity of addresses, but a good side effect of this is that your machines are not raw dogging the internet. I don't want every single device I have to have it's own IP on the internet. I like having a local network. And you can do that with ipv6, but it is just assumed and the default not to work this way and to get everything set up like that is a pain in the ass.