[rcsorensen]

Like `ssorallen says, slow CPUs and limited battery life is an issue. In addition, latency on mobile networks is rough and should be avoided for your users whenever possible.

You have two choices when taking an SPA approach:

1) Give your users a webpage that is usable, readable, and navigable as soon as they get it.

2) Give your users the skeleton of a webpage that they then have to accept the latency of javascript parsing and execution, and then the latency of data fetches.

we have the ability to do #1.

[rgbrgb]

SPAs reduce the latency of data fetches because each new resource is a few bytes of JSON rather than some kb of HTML.

[rcsorensen]

Of subsequent data fetches. Not the first page load. Using JSON fetches to update documents also gives you the ability to not throw away the DOM/CSS and maintain the execution context.

If you use the right technology, you can give a usable application out of the gate without waiting and use JSON data fetches for every subsequent request.