Speed Test 2:
To measure the drive speed again we took a second benchmark utility called NeroCDSpeed from Eric Deppe. CDspeed has a more tweaks than Transferspeed.
The test with F22 Lightning3 gave us the folowing results:

The average speed in comparison with other CDRW drives
The speed at wich the drive starts to read – The bigger the better.
The reading speed at the end of the CD – The bigger the better.
The different seek times – a small improvement in comparison with the Lite-On 241040
The smaller the better.
Conclusion:
The Plextor hasn’t increased the reading speed drastically. The 40x is true and we see a little finer tuning than the 16x. This is resulting in slightly faster reading times and reduced seek and recognition times. The burst rate has also improved a lot.