Used case and screen protector on Thunderbolt for the longest time. Living near the coast, sand tended to find a way in to my cars, my clothes, and yes, it worked its way into the spaces between my phone and my case. Then, *grind,grind,grind* and voila, my phone is all scratched up. So I did the only logical thing, which was throw the case in the trash. Dropped phone at least once since, on a hard floor -- undamaged. Figure I won't go back to cases.