I have heard that an unnamed ISP has switched their DNS servers from Bind to something much better — PowerDNS. I, personally, use PowerDNS and I have only positive things to say about it. As for the ISP’s switch, I hear that they reduced they farm of ~190 Bind servers to ~60 PowerDNS servers. Impressive no matter how you look at it! If you are about to set up a DNS server, I suggest you look at PowerDNS.