> Older iPod Touch models were more prone to damage due to having a soft metal backing. The newer ones, I'm not sure, but they are probably a bit more resilient.
> Most cases won't absorb shock from impact if dropped unless you specifically buy ones which have that in mind. These cases are usually big and rubbery, or have fat corners.
> Cases make the device feel and look less appealing, and its more bulk in your pocket
> My 32GB iPod Touch 3rd Gen has some light scratches on the screen, but you can only notice them on the bezel. Having used it for years with no protector, being rather rough with it, I can say that the likelihood of damaging the screen with a distracting mark is low.