Each stonchip is different, and pretty much unique. There are a few different types. Some easier to repair than others.
The DIY kit is ok for some chips but fall way short of the mark with the more complex repairs. Having said that, there are many [alleged] professionals out there who don't know what a good repair looks like never mind how to achieve one.
http://www.glasstecpaul.com/helping-you-understand-the-ballocks-from-the-********/
