For the media question, you should check the PDF on the Pioneer website for the details:
http://www.pioneerelectronics.com/pio/p ... Speeds.pdf
You should download the latest firmware too. For your convenience, I found the link for you http://www.pioneerelectronics.com/pna/a ... 90,00.html
The performance (ie. speed) isn't affected by the jumper position. The jumper configures the drive as a slave or master. If the device is the only one on the cable, it should work without the jumper. I recommend you move the jumper to master anyway, unless you plan to put it as a slave on a cable.
What DOES affect performance is that you use an 80-pin IDE cable. Most of the IDE cables today are 80-pin. Just make sure you are using that type to get 16x speed DVD.