is there a difference in sound quality when burning with different brand CD-Rs?
All things being equal, there is no difference in sound quality..
I want to say "no" because data on the CD-R is exactly the same as the original CD when it is duplicated properly no matter what brand you use of recordable CD. The data is also digital, not analog.
Again, all things being equal, the digital audio information on your discs is identical..
That said, for best results, using a good/reliable burner and equally reliable media combination is your best bet..
And no! you can't take that to the bank!..JMHO, and of course using my own ears..