[Xylakant]

> I just want to understand what its killer features are.

It's convenient. It understands a lot of static website generators, runs the build, makes a preview, manages domains, DNS, https via let's encrypt. All in a single package. Nothing in that package is impossible doing by yourself, but it's just well executed.

[indigodaddy]

I wonder if using Netlify's DNS with a subdomain only would work properly if you delegated only the subdomain and not the top level name to Netlify's DNS servers...