Sirius radio quality vs redbook cd player

No where near the quality of a well recorded RBCD, IMO.

I can't speak to playback through a home stereo system, but when I had Sirius for the car, the sonic quality of the Sirius was really quite poor in comparison to the sonic quality of redbook cds. Also, if you have never subscribed to Sirius before, be aware that they are a nightmare to deal with if you decide to cancel (at least that was my experience and also the experience of a close friend).

I agree with Tpreaves, a 'good' RBCD setup is much better.

+1 for TPReaves, Gz3827, and Charles1dad.

For a rough comparison and ignoring codec issues, etc.:
Sirius internet radio premium specs a bitrate of 128 Kbits/sec (Kbps).
Pandora radio premium -192 Kbps
Standard resolution MP3 -100 to 192 Kbps
Highest resolution MP3 - 320 Kbps
PCM from Compact Disk 1411 Kbps.

perhaps gratioutously, i'll add that although xm/sirius still advertise that they're "cd quality", they're not even close--they sound tinny and compressed even on great equipment. i'm inevitably surprised on the rare occassions i listen to fm at how much better fm sounds than xm. can't fault xm's programming, however--still can't live without it.