How many people here use 8x discs & actually burn at 8x everytime...if so do you have any playback problems or anything...
I use 8X (RiDATA R03) media since it was easy to find and inexpensive but I still burn at 2-4X. Slow but sure I burned a few at 8X for testing and the results were poor with very apparent skipping during playback.
As far as I'm concerned the write speeds that you can get away with are largely based on too many variables (make/model burner, firmware version, make/model standalone, brand and lot of media) for me to say with any certainty what you should or shouldn't do. As a general rule slower burns will be more accurate but the best way to tell is to experiment for yourself. If you can burn at 8X with no problems and want to burn that fast then I'd say go for it