A few things to consider: do you need 16 GB for your music, pictures, apps? Has your media collection grown to the point where you would feel trapped by only having ~ 8 GB to work with? Do you use the iPod functionality enough where you find it inconvenient without the external volume controls? Technically as far as the space is concerned you probably only have about 6.5 GB to work with due to the iPod OS and the formatted state of the drive. These are only questions you yourself can answer, because what do we know about how much content you need to take with you everywhere?