Performance implications of client-side rendering and Fibers in Meteor

Question

A lot of people have commented on how Fibers (which gives you synchronous code in Node.js) breaks compatibility with 99% of npm packages. I'm more interested in the performance implications.

Does this undo the "Node.js is really fast, look, it's asynchronous/event-based!" argument? What is the practical implication of the Meteor team baking in Fibers?

Also, after deploying a huge rewrite where pages were rendered on the client-side, Twitter reversed their decision in favor of serving HTML from the server to improve page load times. What does this mean for Meteor's potential performance limitations (especially on first page load)?

Answer 1

The development team is planning on implementing server-side rendering to work around the first page load issue as well as to support search engines, by sending the initial data that is shown to the user as part of the HTML he gets to see the initial data while still retaining all the rest.