The previous (kmix) system tray icon allowed for pulling up a mixer with a list of individual playback streams.  This was provided by a prominent button labeled "Mixer".

The new Audio Volume widget provides a right click menu to access the "Audio Volume" system settings menu.  This menu provides the same information as Kmix, excluding the missing icons and event sounds bar.  Unfortunately, it does not provide a method to move applications' audio to a different output.  Kmix allows for this using a "right click -> move" option.

Reproducible: Always

Steps to Reproduce:
0.  Have more than one audio output device
1.  Open old Kmix mixer
2.  Select the "Playback Streams" tab.
3.  Start playing some audio
4.  Right click the audio icon on the "Playback Streams" tab
5.  Select Move, and move to another audio device

Actual Results:  
0.  Open "Audio Volume" System settings.
1.  Notice That application icons are missing.
2.  Note that right clicking does nothing.

Expected Results:  
0.  Open "Audio Volume" System settings.
1.  Application icons are shown.
2.  Have an option to select which audio output is used by the application.
2a.  Optionally show each application's current audio output (combo box?)

I have a USB headset, mixed with regular speakers.  The ability to switch applications between them is essential to my use case.  Since I'm, probably, in the minority I'll just continue using Kmix and this can go in the wishlist.