I'm having problems broadcasting and subscribing with WebRTC. Sometimes it does not connect and when it does the image quality can be bad.
Most WebRTC platforms do not work (or do not work well) on Firefox. For example, Google Hangouts or appear.in both have issues. Unfortunately, there isn't anything Red5 Pro can do to fix this as it is beyond the Red5 Pro product. Our investigation into this revealed that it has to do with how Firefox handles websocket connections. You can find more information about it and vote for fixing the bug, here: https://bugzilla.mozilla.org/show_bug.cgi?id=1288995#c15.
Additionally, Firefox restricts bandwidth no matter what settings are passed in, so that complicates image quality issues as well.