[callum85]

Several comments are misinterpreting the article, I think, as saying that your site will be slower than before when you switch to HTTP2 if you're still using the old techniques. In fact, nearly all sites will just magically speed up thanks to basic improvements like header compression.

But, by continuing to use the old hacks, your site won't be as fast as it could be. It's an opportunity cost. Some of those opportunities being:

- increased cache granularity (avoids invalidating a whole sprite or concatenated bundle when just a single part changes)

- parallel downloading of files that were previously bundled into one file

- fewer DNS lookups, now that you're not sharding

- less energy/memory usage in the client because you're not decoding/remembering whole sprites

And the subtlest, biggest win:

- simplifying your build process.