Just tested stremium on their testnet. The audio-quality is like 96 kbps. No really good for streaming audio. I didn't test video, but I think it's slow and not usable for stuff like "instrument lessons". If the quality of the stream will be better, this might be a great thing.
I also had problems with connected to a test-stream I created. The problem was, that NoScript blocked some sites you need to watch / hear the stream. The problem was, that I paid for a session (20 minutes) and after the payment was received by Stremium and I landed on the stream-page, I had to allow some sites / scripts and after that, the site reloads and I wasn't on the streaming-site anymore, so I had to pay again. I don't know, if the payment from the first time was paid back, but that's a big problem at this moment.
I was wondering how the audio turned out. I had a feeling you would be doing "instrument lessons" which would be very cool. The thing with Streamium is its def. in Beta mode. Did you get your payment back from the first payment ?
edit: update on Streamium
http://www.reddit.com/r/Streamium/comments/378xxy/announcement_updates_to_streamium/