TYG02 burn equally well as TYG03 overall in drives that have proper support for the both of them. In the limited scope of user testing on the forums, TYG02 has actually shown itself to have better quality (limited disc scan quality, playback tests) than TYG03 on many occasions (as has YUDEN000 T02 over YUDEN000 T03). Typically, TY’s 8x media is thought to be of a higher quality than the 16x media sold under similar brands/labeling.
As long as you avoid so-called value-line discs, you should have a low risk for poor burns.
But I support the idea of just grabbing the 8x Taiyo Yuden DVD-R (or the 8x DVD+R, YUDEN000 T02, if you like) for the 8x drive in the future.
Check on Apple’s site to see if they ever released a firmware update. If Apple has ever released a firmware update for your drive (take a look around Apple’s web site and see if any of the few optical drive firmware updates apply to your Mac model), see if the update mentioned support for 16x media. Some 8x drives were able to get along relatively well with 16x media after a firmware update.
If Apple doesn’t have anything, then check Pioneer’s site. Be warned, though; you might need access to a Window’s computer for the easiest flashing process, and you might have to use a 3rd party flashing tool. (Just for what it’s worth: Flashing a non-Apple firmware would likely void the warranty on the Super Drive since you are no longer using an Apple-shipping firmware version).