Does Replay AV support recording two Sirius channels at the same time? I can think of a couple of instances where my favorite shows overlap, and would love to be able to record both.
I would say yes, you can do it, and this is how: Set up TheEndless' SiriusStreamer program (SiriusStreamer - Sirius Internet Radio Stream Proxy), then, re-create your scheduled recordings as standard stream recordings (not "Record Sirius"), using the URLs for the channels that SiriusStreamer provides.
I do use this method to record Stern every day although I haven't tried recording two shows at the same time. I have been able to tune two different channels at the same time with success though, so I imagine it would work.