Please check these links and give me your valuable suggestion. Thanks
http://www.dvd-recordable.org/Reviews+index-req-showcontent-id-100-page-2.phtml
http://www.dvd-recordable.org/Reviews+index-req-showcontent-id-96-page-6.phtml
http://www.dvd-recordable.org/Reviews+index-req-showcontent-id-96-page-2.phtml
This review is very old… 
And in the second link the Pioneer burned the disc at 4x… but the Nec at 16x…
I have found
4x/8x -r media does not work very well on 16x burners, best to buy 16x media for a 16x burner
In the UK buying any 16x burner is a big mistake, there is no 16x media available to buy, the 16x burners have poor results using 4x or 8x media (poorer results than an 8x burner using the same media anyway) and your 16x burner will be superceeded by new models by the time you can buy 16x media, so just wait.
I also have a question about NEC 3500A : does this drive have good results when burning to Verbatim 8x DVD-R media? If not who does ?
Thank You!
no way no mistake here…My 3520a rocks… I never got to burn at its top speed yet, I do burn my 8x media at 12x with modified firmware. I dont really need anything faster than 12x
I was eyeing both this drive and the liteon, but went with nec.
@lordkv
The NEC 3500 can produce very good 12x and even 16x burns if you use good 8x media, such as (Taiyo) Yuden T02, but you have to make sure you get the real deal and not fake TY’s, and use the right firmware. There are a lot of topics about media and firmware on this board to help you with this.
@sarahjh69
If you cannot find good media in the shops, you might take a look at www.os-mediatrade.de . I noticed they ship to the UK as well.