The main benefits I can see for node are performance, ability to use the same language on front and back end, and possibly easier server side rendering for SPA

The main benefits I can see for node are performance, ability to use the same language on front and back end, and possibly easier server side rendering for SPA applications. I don't think node comes out ahead in basic CRUD productivity as the rails ecosystem has many robust gems, established patterns, and documentation due to its maturity. They've recently added yarn and webpack integration as well so the core team seems well aware of the interest in SPA support. It's a little tough to gauge though, since rails is a close to all inclusive framework while node's frameworks (ex: express) tend to favor smaller pieces you combine together yourself. There are pros and cons either way.