In a message dated 11/18/1999 7:50:41 PM Eastern Standard Time, daveb@CP.NET
writes:

<<  my golf currently has two large spidered cracks from *small*
 pebbles hit at around 50 mph. The pebbles made small cracking
 noises...
         My stock vanagon windshield recieved a nice chunk of
 gravel kicked up by a semi up in canada at 80 km/h. The chip
 is hardly noticable.
          Anyone know of anyway to compare glass quality? >>

I'll go out on a bit of a limb here:
i think the difference is far more likely to have to do with the angle of
impact, shape of pebble, and such, rather than windshield quality.  Another
possibility is the (re) installation.  If the glass was replaced and was
slightly "tweaked" or otherwise stressed, it could be more susceptible to
impact fractures.
I doubt if you could find much difference between various replacement
windshields available...
Doug
(former glass shop employee)
84 Westy
SE PA