I print a big volume of discs for companies and use both silver and white. From my experience with printing thousands of those I must say both are good and have their use. For the most part, silver will give excellent results,particularly for text and graphics, it will give it a shiny, proefssional look as most of the music CDs you buy are done this way. There are some times where white is more appropriate, it depends on your personal taste - Unlike pressed CDs which use silk screening processes, I have noticed that the silver CDs/DVDs are more sensitive to scratches (the printing surface). Example, someone gave me a set of Prodisc silver printable discs to print and have noticed that if you barely scratch the surface you can easily remove the silver coating and see the shiny non print surface beneath whereas with my white taiyo yuden printables, the coating is much more resistant and will not come off that easily.
For Audio CDs I would favour silver printables and for DVDs I would use white. Of course if your template is based mostly on photos, I would go for white as well. Coloured text and hard surface graphics would look well on silver as well.
