Are coating makers saying that the harder a coating, the less likely it will etch or be susceptible to environmental fallout, OR is it a function of durability and lifespan?
I assume then they are using this as "gauge" to measure and quantify the armour-like quality of their coating and hence, a way to market and sell this "gauge number" to the car-care buying consumer as proof of enhancing those desirable coating characteristics.
Here are some reasons/criteria for using any Last-Step Product (LSP): (I had posted list of reasons somewhere before, but I could not find it, so this list is to my best "recollection"), not in any particular order:
1) Reflectivity or gloss (AKA exterior surface appearance)
2) Resistance to environmental fallout or debris (AKA, Protective properties against bird dropping, bug etching, acid rain etching, rain water spotting, UV fading-resistance)
3) Self-cleaning properties
4) Hydrophobic properties (AKA, water beating or sheeting)
5) Longevity (How long it last before requiring re-application)
6) Ease of application and removal (may require special application pads or removal clothes AND/OR curing UV lights)
7) Compatibility with other manufacturer`s products (especially after compound/polish correction)
8) Special post-application care (maintenance detailing sprays and required wash-soap types)
9a) Initial cost (product cost)
9b) Cost per application (also includes product size availability)
10) Product availability (Over-the-counter, boutique, certified-installer/dealer only)
11) Warranty with product (from coating manufacturer)
12) Product shelf life (important to a hobbyists who may use the LSP for a few cars in a year, but had to make major investment in buying some "larger" quantity of an quality-LSP to get a cost-effective price)
13a) Manufacturer`s product reputation
13b) Experience with manufacturer`s products
So which of these properties/characteristics/criteria does graphene have over other LSP`s and is it cost-effective to use?
