Yes, it is stuttering right now. Especially when it is in the background. We think this is a buffering issue, but yes. We hope this will be able to go into production soon(tm).
FWIW, I'd love to see support for icecast or shoutcast streams.
As long as they contain only MP3 files, that would be really really easy to do. If someone does it on Github, please ping me - we'd love to host it on jsmad.org