During my training, at one point, I helped in a BIND4-to-BIND9-migration. I learned more about DNS than I ever wanted to know (and then even more to avoid having to learn Rexx). (I have forgotten most of it since.) I set up a DNS server for my LAN to see if I had understood what I had read.

Haven't looked back since. The main advantage, initially, was performance, but it has other advantages, too.

Although, now that you mention it, I kind of do use BIND9. It hasn't been that much work over the years, really. I am open to alternatives, but so far, I have not found a solution that would be easier to maintain and serve both as a recursive resolver and as an authoritative nameserver for my local zone. (I do admit that I did not look very hard, because the current situation with BIND works for me.)