Burning process completed at 9 minutes, with no drive motor slowdown. Actual speed shows 2~16x, because this compilation contains ~20000 files. (many variable-sized files and too much <10kb files - its a hard drive backup and my harddisk drive not fast enough to stream necessary rate of data) And I noticed a number times BenQ's LED still green(not blinking). I thinking, at this time my computer doesn't provide enough data, and disk buffer and empty because of writing process "paused".)
As keyap's suggestion, I tried 8x burn & scan: quality points are +1 above, and less PIE&PIFs. I think between 16x and 8x burning scans shows small differences. In yours opinion, should I change the firmware and try again or this results are enough. In attachments, you find a 8x burn & scan results. Sorry for my bad English.