Quite effective.
These nano coats are pretty popular.
But they serve a different purpose than say a "clear bra" like 3M?
Yes, the clear bra (like Xpel for example) is highly effective for preventing rock ship. So most people opt for that on the front, hood, mirror. Nano coatings prevent scratches, swirls, etc. Think of the nano coatings as a super-duper, durable wax job. That just a basic explanation...but should give you an idea.
Negative....Nano coatings don't prevent scratches or swirls.
Sigh....lessen swirls. Or perhaps "help to prevent" swirls. Or maybe "resists swirls". Or "reduce swirls". Nothing can outright "prevent" swirls or scratches as far as a coating goes...I mean it's only a few microns thick. But compared to untreated paint...it will lessen them (or choose whatever word you want to make you feel warm and fuzzy).
I was present for a "test" on 2 panels. Both were pristine black paint. One was coated (I forget if it was CQuarts or Opti-Coat, etc). And a dry Kleenex-type tissue was rubbed across both. Under light, you could clearly see the scratches/marks/swirls on the unpainted one. And nothing on the coated one.
So call it what you want. But in the case I saw..I'd say if definitely prevented the fine swirls/scratches (even if you disagree with the word "prevent").