MattIM said:The first time I used a screen protector was on a Palm. Later, I bought a Sony A700 DSLR, and a Zagg shield went on its LCD display. When I got my first iPad, Zagg shield. Ipad2, Zagg shield. Now that I have acquired the third gen iPad, I also Zagged it. BUT I had to return that one due to faulty screen. Best Buy told me to contact Zagg and they replaced it. While waiting for the Zagg to arrive, I started using the new iPad without a shield and it felt different--finger directly on glass. The Zagg had arrived and I still have not installed it on my iPad. It is a naked iPad (in a protective case) and going two months, no scratches.
This is one of those issues that I think boils down to preference and individual behavior. To this I say YMMV.
A lot of those early units either used plastic screens (palm) or very soft glass for screens that are not normally touch. This would result in less shattered screens but far more scratches than using early hard but brittle glass. It's simply not the case these days (if you excuse the pun).
However, I will says a good case is the only chance of saving an iPad from inadvertent knocks when traveling with it. Screen protectors may make you feel good but do nothing.