I have also embarked on a similar project.
BIND is bloated, memory management was not a programming priority apparently, and its cache design is laughable. Asides from that its works fine. :)
DJBDNS is another kettle of fish - its FAST, its pretty secure, and its smart -- But DJB has this really nasty habit of deciding all/part of an RFC is "stupid" and just doesn't bother implementing it, to hell with anyone else who actually expects DNS servers to be RFC compliant.

My server also uses Net::DNS, however its somewhat more expansive with "intelligent caching" (self lookups when load is low on his tasks, dropping off least used cache entries when the cache is full, that kind of stuff), the zones are SQL based and centralised, removing the requirement for zone transfers, dig their own root servers, random junk.
Works REALLY nice, except Net::DNS is painfully slow, which makes it quite useless in practice. Net::DNS is written entirely in perl, which is wonderful for educational purposes, but unfortunately pointless for real service - and Net::DNS hasn't been touched in a few years, if I remember correctly... Oh well

Anyone want to rewrite Net::DNS, and this time in C? :P

JP,
-- Alexander Widdlemouse undid his bellybutton and his bum dropped off --