Here are my top 5 reasons why I think qmail + daemontools + djbdns is great :
1. bugs free code ( well almost ) ;
2. fast & memory efficient ;
3. following "everything is a file" philosophy ;
4. easy to configure and more
I've been using this suite for almost 10 years now. I've never found any alternative. BIND was too complicated in terms of configuration for me and also got updates almost every 2 weeks ( 8 years back it was much much harder than doing "apt-get ..." )Qmail is also flawless piece of software. It basically taught me how you should separate processes and how to use linux accounts properly for the daemons. Amazing.
Finally the only thing I rely on right now is daemontools. I'm using it for all of my production nodejs websites and even for a tool that I call "deployer" which automatically stops, updates and starts a daemon from the suite.