It's ok to be pedantic!
The quality of the audio will not change from 2x to 12x, however the quality of the burn will change.
Even though you may not suffer a buffer underrun and completely stop (or have burnproof protection) the speed at which you select can determine if you will end up with pop's or clicks on the burnt CD.
I've found that if the buffer get's down to 10% or even 1%, on some burns, I'll notice what it was burning at the moment, and in that track (for audio) I end up with unwanted clicks or pops. This has to be due to the data stream being slowed down, etc. (But not causing a coaster, as burnproof supposedly holds the last position of the laser until the buffer is replenished, etc.)
anyways, that said, the point is that even if you have a xx speed burner, depending upon hat is being burned, and your system, the top speed is not always the right speed. the errors come from data interruption, not flaws in the audio being copied (unless of course, your audio had the flaw to begin with).
And yes, each burner has different CD media that can give varying results even at a sloweer burn speed. the type of dye used (color) etc. can either be acceptable to your specific burner, or not. I've found mine loves the blue dyed CD-R's myself.
Just my .02.
[ 17 December 2001: Message edited by: RW-1 ]