The fight between your average video game and NAT has caused me so many problems over the years (including port forwards to receive traffic because whatever NAT punching mechanism the game used didn't work).
Running dual stack does cause some weird debugging ("why can't my laptop connect to github while everything else works? Oh, DHCP broke") but that's mostly because of problems with the IPv4 part of the network.
I think going IPv6 only isn't the way, not yet anyway. DS-Lite seems to be working fine as a replacement, though: CGNAT for IPv4 and normal IPv6 for real connectivity. Full fat dual stacks would be better, but realistically I don't think that's going to be brought to the masses.
For hosting stuff, not having to remember what SSH port maps to which server in my home lab is a nice addition. Being able to directly reach LXC containers is also quite useful, as is using separate addresses for individual hosted services.
I don't know why everyone here has such terrible ISPs. Unstable IPv6 prefixes, broken routing, weird custom allocations, your ISPs all seem so cursed! No wonder people are so mad at IPv6, your ISPs are sabotaging your internet.