That's why we try to provide as much information as possible mostly at our own cost. If somebody didn't read those posts and still complain what media do not work at the rated speed, this forum is not the best place to complain. Instead, test properly and report the results here so that OTHER USERS can know before they decide on the type of media they are going to purchase. Since not everyone can afford buying all kinds of media distributed in the world, lots of information will be left out and just the more people provide voluntary test results, the better. Unfortunately, only very few people seem to do so here. For best results, use only the types of media that are widely reported to work in GSA-4163B with the best results. If you want to keep the drive, I mean.
A103 firmware will soon be released, if not already, but more media support and higher write speeds will probably be added in even later updates, if any. Again, without proper reports and feedbacks on this forum, I don't think there's going to be much change in the media compatibility policy. That was one of the very reasons why I proposed this forum but so far member participation has been nearly zero. For better "community" support, just use one of the latest 16x DVD writers from Lite-On or NEC or BenQ.