The reason I prefer IPv6 over IPv4 NAT is it gives me the option to use the same ports on multiple hosts on my network. IPv4 NAT is quite crippling for some of ujs (who also happen to know how to manage our firewalls ;) ).
Yes of course NAT is a pain when doing special things, but for most internet users it is not a problem at all. Especially now that the internet has evolved from a peer-to-peer network into a traditional client-server network where a few big companies run all the services and the users connect only to there, even when they want to communicate with another user.
What I like about IPv6 is that it gives me out-of-band management of IPv4 networks. Yesterday I did a major restructuring of our AMPRnet-Internet gateway, where a MikroTik CCR has been added to the existing PC Linux solution to take over part of the services, and I could make all the network topology changes with confidence that I would not lock myself out, using IPv6. That is also handy when managing the very complicated IPv4 firewall.
In fact so many users have been completely accustomed to NAT that they even apply it to AMPRnet... Putting their systems on RFC1918 addresses and translating it to net-44 addresses in the router. I would not do that...
Rob