Curious, actually. Years ago when I looked at djbdns it was very controversial; considered to not play well with others (for example, no support for slave DNS, which is an important part of the world's DNS structure, though not part of Dan Bernstein's view of DNS.
Don't get me wrong; I'm not against Dan Bernstein's products at all; I think Maildir, for example, is much improved over mbox (though perhaps a bit more complex than it needs to be). But for example, if DirectAdmin had started with djbdns instead of with BIND, it would have been impossible to easily do master2slave DNS Replicator.
Keeping two copies of DNS, the master files used by DirectAdmin (BIND-compat8ible zone files) is after all, at best a waste of space, and as an old school database designer who used to care a lot of database optimization, that sort of still bothers me on some level. In fact just this past weekend I touched on the subject of data normalization with Mark (the M of JBMC).
But djbdns zone files are very efficient, and wouldn't take up much space at all.
I couldn't have used djbdns in my infrastructure until recently because we offered Slave DNS services. But we're moving away from that now, and in fact I could even consider using djbdns for it's efficiency (if it protects against duplicates as Master2Slave does, and as according to a recent thread in these forums, DirectSlave fails to do).
Jeff