I haven't as yet had to replace my windscreen, (touches wood), but if I do I shall insist on having the Pilkington Glass fitted. Its a little known fact that you do actually have a choice of windscreens when being fitted by the insurance.

Years ago I had a Honda Civic Type R and the belief was it was fitted with a lighter, yet tougher windscreen. When it cracked I insisted the Honda dealer sourced the windscreen and fitted it. The insurance agreed provided that I pay for it myself and then claim it back which I did successfully.