I don’t agree that you usually would still use NAT with IPv6. I’ve never seen NAT in combination with IPv6 and I’ve seen plenty of deployments at our customers. NAT is not the same as a firewall, so just using public IPv6 addresses does not mean that you are exposing every port by default. I think you should read up on IPv6 and firewalling before making statements like this :)
Edit: you don’t even have to set up firewalling on each internal device… the router/firewall blocks inbound traffic by default.
/120? /48 and /64 are common assignments, where /48 is imho preferred as it allows you to easily use SLAAC inside your network. I’ve seen plenty of home setups too and I don’t know how to say this nicely but you should really read up on IPv6 before posting comments like this pretending you have an idea what you’re talking about. Seriously.