Disagree. Unlike their IPv4 setup, where the IP rarely changes, the IPv6 address constantly changes for no apparently reason. This makes it hard to whitelist IPs or to set up an internal IPv6 network.
I ended up getting an IPv6 /48 from Hurricane because of the hassles. That works great (other than having to force Netflix to IPv4 because of their dumb IP block).
If Comcast offered static IPv6 (NOT via business class), and more than a /60 (/58 at least), that would make it "work great".
