> Never again will you have to hunt through your tabs to pause your music,

> Supports media keys (play, pause, stop, next, previous)

A relatively recent Chrome feature that many aren't aware of is the ability of extensions and apps to use Chrome- or desktop-wide (global) hotkeys. So if you're using the Google Play Music extension, you can, for example, hook it up to your media keys and it will work even when Chrome isn't focused. Go to chrome://extensions/ and scroll down the Keyboard shortcuts to learn more.

(I'm sure that there are many other reasons people prefer desktop apps, but this was the big one for me.)