HardwareZoom has posted a review on 5 main brands (TDK, LG, Sony, Pioneer and BenQ) DVD-writer

All the drives are capable of 8x DVD+R writing except Sony. From the performance graph, there seems to be some problem with the results from Benq, it shouldn't be writing constantly at 6x. Nevertheless, if we compare the graph for Pioneer, TDK and LG, we can see that Pioneer will hit 8x at around 600MB, while TDK and LG will reach 8x after writing 2GB of data.

Read more