I migrated a couple of sites I look after from react-static (which is a nice, simple library but unfortunately had some fundamental issues that it sounded like we’re unlikely to be solved and gave the impression that it was struggling for maintainers e.g. https://github.com/react-static/react-static/issues/1203), one to Gatsby and the other to NextJS.

I agree largely with the findings described here - Gatsby felt quite slow and the GraphQL part feels like complexity overkill, for my use case I bypassed it using their createPage API but you lose out on eg the ability to reload a page’s data on the fly by doing so (from what I could work out - the documentation was a bit lacking in parts I found).

I was more impressed with NextJS, it feels generally more solid and easier to understand. It has a great preview feature where you can set a cookie and then the site will pull in data at request time rather than from the static site (perfect for CMS previews!) and build times seem alright - I haven’t had cause to look into speeding them up, which is a good sign.

Personally I’d go with NextJS in future based on my experience... that said, I’ve no idea if it would work well for their reasonably specialised use case!