FWIW, IPv6 has worked just fine for me since they enabled it (I don't think I had it when I initially got them as my ISP). I also have found them pretty responsive to even technical feedback, but maybe I've just been lucky.Of course, there was that one time they "upgraded" our building and forgot to re-plug my line to the router, but, oh well..
Overall, this seems like a super niche topic for HN. :)