I did. A good chunk of that chart (addresses, DNS, autoconfig, ARP/NDP, IGMP/MLD) is a result of changing the address size. Some parts of it are incorrect (IPse

I did. A good chunk of that chart (addresses, DNS, autoconfig, ARP/NDP, IGMP/MLD) is a result of changing the address size. Some parts of it are incorrect (IPsec) or aren't a difference (multicast). Many of the parts that are left don't seem like a big deal (minimum MTU increase from 576 bytes to 1280 bytes should be trivial, especially since 99.9% of people use 1500 bytes via PMTUD anyway). NAT isn't even a part of v4 in the first place, it's an additional thing that you bolt onto the side to try and deal with not having sufficient address space for your network. Since in v6 you generally do have enough space, you simply don't need to do that -- which is good, because NAT complicates your network and makes it harder to reason about the behavior.