You don't need to use nat on ipv6. Most routers are based on Linux and there you have conntrack.
With that you can configure by default outgoing only connections just like nat and poke holes in the firewall for the ports you want specifically.
Also windows and I think Linux use ipv6 privacy extensions by default. That means that while you can assign a fixed address and run services, it will assign random ip addresses within your (usually) /64 allocation for outgoing connections. So people can't identify you and try to connect back to your ip with a port scanner etc.
All the benefits of nat with none of the drawbacks.