The protocol takes care of most things if default settings (e.g dynamic addressing, subnetting) suit you. Predictable addresses are messy. Changing ISPs is a n

The protocol takes care of most things if default settings (e.g dynamic addressing, subnetting) suit you. Predictable addresses are messy. Changing ISPs is a nightmare unless you run NAT. Firewalling being decoupled from NAT is a more complex experience. Memorising addresses becomes much harder. Old devices have varying support and common brand routers still have various IPv6 bugs. I have IPv6 running at home and love it, but familiarity and comfort aren't the primary reasons it's less managable. Many existing configurations simply don't translate across very well.