These discs can be good with the right burner. Sticking to 4x will ensure a good burn, burning at 8x may depend on your batch.
what i've seen:
- Lite-on 451@CG5G = acceptable result @ 4x
- Nec2510a good result at 8x (depending on batch)
- Nec2510a Excellent result at 4x
Being a Gigastorage (Taiwan) disc they aren't comparable to the 'best' discs on the market, but for budget discs these are very good. Of the 4x GSC001 and GSC002 discs i have used for the past year, i have had good burn results and the discs have lasted well so far.