As a Happy Hetzner customer I've been using their dedicated server and cloud VPS offererings for years. Only recently I started using their free DNS hosting option. Not sure why it is free, but it is and it is nice.
It offers API access to update records which is great. But this weekend I noticed that when creating new DNS records, it will actually autofill/suggest the IP adresses of hosts you are leasing at Hetzner at that time. Nice, makes it all somewhat easier and less error prone.
Most important gripe I have about the service is that is does not seem to include a DNSSEC option.