1. It works quite well, is very light on the memory/cache, & is capable of being downsized to where it's not in the way of the reader's site-viewing experience.
3. It's usable with various sound files, but not all of them [.mp3 / .ogg / .wav].
4. There aren't many options out there for background music/sounds that are less-invasive such as this one & have the option to auto-follow the screen instead of having to be placed in a widget.
5. Other things to note: auto-play capability, looping capability, customization for each page/post.