Slow reading (and burning) [GSA-4163b 1.05] [newbie question?]

Disk info:
Manufacturer : Verbatim
Code : MCC 03RG20
Disc Type : DVD-ROM (Book Type: DVD-R)
Usage : General
Recording Layer : -
Recording Speed : 4.1 X - 16.4 X

Doing nero speed test on a full data (or video) DVD, top speed ends up to about 10x speeds with average of 7.7x. Is this normal? I would think that the drive would at least on some point reach the 16x speed. And the same with writing: with 8x speed, it writes about 8 minutes. Using 16x speed cuts the writing time to about 6:30. Is this normal or slow?

And while I’m typing newbie questions, here comes another one. I just learned about the DVD-bitsetting. Have I understood right:
My (old PS2) doesn’t play DVD+R. With DVD-bitsetting I can adjust the DVD-type bitfield when I burm DVD+R so that my PS2 will think the disc as DVD-ROM and read/play it?

Please feel free to point me to the right FAQs if these are FA questions (tried to go trough some FAQs first)

  1. 6:30 for a full dvd at 16x is normal.

  2. Depends on the Ps2 and it’s drive, there are many various types on the market…