Physically, SP is unneeded. It is really not that easy to cause scratches on the screen.
Mentally (or should i say emotionally), people want it because it makes you feel safe.

From my personal experience, last year there is finally one day I made up my mind to stop using SP on my iphone/ipad. And since then I had never spent a single buck on SP anymore. Until now, there is no visible scratches or whatsoever even if being examined carefully under light.

For my iPhone, I use only the kind of casing which only covers the back part, so the screen is exposed all the time. I always drop my phone into my gf's handbag mixing together with lots of other stuffs like keys, combs, etc. But it is better to avoid doing that especially for iPad unless u're using a casing for it. Speaking of which, almost everyone uses a casing for their iPad, so why buy a SP?

This post has been edited by FinFin: May 10 2012, 09:47 AM