CD Speed 99 - CD-RW
Finally, the CD-RW tests:

Plextor 12/10/32A reading CD-RW

Drives typically take a performance hit when reading CD-RW media due to its lower reflectivity. The 12X Plextor continues this trend, dropping to an average speed of 16.89X. Less typical is the obvious trouble the drive has towards the end of the disc, interesting since the RW disc had few if any scratches. Access times are still better than the pressed disc, however.

Plextor 16/10/40A reading CD-RW

The 16X Plextor also takes a hit, with its average speed dropping to 24.88X. These are still respectable RW scores, however; RW media typically causes a more substantial performance drop, and access times are actually slightly lower.

Samsung 52X reading CD-RW

This is what I meant by "typically causes a more substantial performance drop," as the Samsung just falls apart on the RW test. The 52X drive manages an average speed of only 13.64X, and the end speed of 17.92X is a far cry from the drive's rated 52X.

The previous tests demonstrate how deceptive it can be to judge a drive solely by its rated speed. One would expect the 52X drive to walk away with wins in every category, but it barely eked out one victory of three in the file copy tests, and it was decimated in the CD Speed RW test. Plextor has a reputation for going the extra mile in engineering, and these results bear that out.