You gotta love the Orwellian naming on this one. "Ember FastBoot" meaning Ember-we've-been-selling-you-very-slow-booting-for-years-and-now-we're-hoping-to-mitigate-it-slightly-but-it's-still-vaporware.
Meanwhile, the commonsense approach has always been faster and simpler than this model: Use a small JS framework, not a bloated one, and only load the minimal UI and data set that you need to render the initial page at first. Load the rest later. This includes bootstrapping — remembering to put all the data you need to render the page inline as a JSON object in the HTML.
This can often result in less data sent over the wire than a large HTML page with tons of repeated DOM elements. It's also far easier to cache appropriately.
Meanwhile, the commonsense approach has always been faster and simpler than this model: Use a small JS framework, not a bloated one, and only load the minimal UI and data set that you need to render the initial page at first. Load the rest later. This includes bootstrapping — remembering to put all the data you need to render the page inline as a JSON object in the HTML.
This can often result in less data sent over the wire than a large HTML page with tons of repeated DOM elements. It's also far easier to cache appropriately.