"dnsdist is a highly DNS-, DoS- and abuse-aware loadbalancer. Its goal in life is to route traffic to the best server, delivering top performance to legitimate users while shunting or blocking abusive traffic."
I gave it a shot and liked the interactive console and real time statistics. I only played with it briefly and made it the primary resolver for a branch of about 50 users; it seemed stable and didn't affect performance negatively. I hope to play with it more in the future, applying the testing regime to a dnsdist server may be interesting to do.