SPDY addresses some shortcomings in HTTP, but you will always have to be mindful of the amount of render blocking JavaScript and CSS loaded on your page, regardless of network protocol.
If you load large amounts of render blocking JS/CSS in the <head>, the browser must wait for it to finish downloading before it can render content in <body> to the screen.
To deliver a fast experience, keep the amount of JS/CSS needed to render the initial view to a minimum. Ideally, that'd be no JS, and just the CSS needed to style the content in the initial view. Then, once the initial view has rendered, load the JS and additional CSS needed for the rest of the app.
If you load large amounts of render blocking JS/CSS in the <head>, the browser must wait for it to finish downloading before it can render content in <body> to the screen.
To deliver a fast experience, keep the amount of JS/CSS needed to render the initial view to a minimum. Ideally, that'd be no JS, and just the CSS needed to style the content in the initial view. Then, once the initial view has rendered, load the JS and additional CSS needed for the rest of the app.