I'm using the ST300, AM300, and VI300 for both movies and Spotify in my living room.
For movies, I like the rear speakers to be quieter, and the bass lower. For music, I like to turn everything up. But it's a manual process to change this every time. It would be great to be able to set the individual speaker volumes depending on the input, and to be able to adjust the bass level in the Soundtouch app.