I work with high energy optics, and use microscopes, and specialized light sources every day. So I'm an old hand at spotting imperfections measured in microns. Let me tell you, the launch 8GB iPhone I've used (naked) until the iPhone 4 that replaced it - has not a single scratch on the screen down to 8x. The bezel has a bunch of scratches, and the aluminum on the back is ablated in the corners, got a nice ding from a healthy drop onto concrete courtesy of a coworker... But the display (low res, bland color gamut, crap viewing angle, and light bleed aside) is beautiful.
My iPhone 4 - given the same level of care (perhaps a bit more), never dropped (amazingly), has scratches galore, plainly visible without any localized light source or magnification. I swear, polycarbonate could give the IP4 glass a run for it's money in scratch resistance...