Same with Comcast. I tried for a years actually, but some things were too slow. Ubuntu and Debian repos in particular were painfully slow, even on my VMs on linode, digital ocean, and prgmr. I ended up having the servers force IPv4 for them when their IPv6 servers went down for days. Speed and latency on IPv6 have gotten much worse over the last couple years in my experience.
Also, it appears Android doesn't play nice with IPv6. It basically silently drops the connection eventually (I'm guessing it stops listening for the RA broadcasts), and push notifications fail. Happens on Samsung devices and my Nexus 6. So it's reliable either push notifications and low latency site loading, or use IPv6. I finally bit the bullet and disabled IPv6 on the router and all my issues went away.