Review: Case-Mate - Dress Your iPhone Up Naked
The acrylic completely covers the iPhone - back, sides, and front. And you don't have to use a separate film over the touch screen, like the leather or rubber cases. Over the touch screen the case is a special type of plastic so you can use the touch screen without removing it from the case.
I haven't tried dropping the phone in the case, but my guess is that the naked case will offer some protection to both the phone and the glass touch screen.
I had one issue with the case in June - it seems to trap moisture - humidity from the air - between the touch screen and the case. This isn't a big deal, but it seems like there is a "blob" of something on the screen, and that blob sometimes moves around. Whether or not this moisture blob is present depends on your environment. In the humid South, it is often present, but in air conditioning, or when I was in the Northeast on vacation, it wasn't. Not a real problem.
My other concern was whether the acrylic case would scratch. But after 4 months carrying my phone in my pocket the touch screen surface has not, however, the plastic on the back and the sides do. The original beauty of the case is still there, just a few scratches. Lint from my pocket does seem to build up inside the case.