There is a video online floating around by someone who put about 40 different coatings on a test hood and did periodic updates on the status of each product over the course of about 2 years. It has longevity test results for some of the coatings you're looking at. Pretty interesting results!
And who were the top three, Nick?
While I certainly admire the time, effort and expense that went into that oft-cited test, it's my opinion that unless they strap that hood to a car and drive it around, it only tells part of the story with regards to a coatings performance, a good starting point if you will. In my climate, merely sitting outside (maintained or not) has very little effect on coating longevity when dealing with quality products. Driving, especially on freeways in the winter, is an absolute LSP killer. To wit:
We have 2 cars with considerably different usage patterns; both protected with same set of products/coatings:
1. At 3 years, 17k miles, Car 1 was still performing (w/ regards to coating) at about 85% 'as applied'
2. At 2 years, 42k miles, Car 2 was in need of re-polishing and re-coating.
1. Car 1 is about 5500 miles a year, no freeway, sits outside from April thru November but only really driven daily November thru April, short trips, no freeway.
2. Car 2 is year round daily driver, generally always garaged, 25k miles a year, 95% freeway.
Both are in NE Ohio.
Same protection, varying usage far different likely outcomes. Freeway use, especially during winter, is very, very hard on a vehicles finish. Road salt, brine, chemical de-icers, road grime ain't good for anything regarding a cars finish. Merely sitting outside in the elements has little effect on (this particular coating) coating degradation.
Point being, no claims listed on a box can even begin to adequately predict longevity. It's the ultimate YMMV scenario. And in NE Ohio, longevity based merely on the passage of time is a poor barometer of coating performance. Heck, I can take a 6-month 'coating-lite' product like Gyeon CanCoat, plop it on a car that only goes out in nice weather 3 months of the year and it'll last for years.
I (personally) think that for cars that are actually used/driven, unless coating is a self-healing product (that actually works), anything beyond 2-3 years is pointless for someone who is mildly OCD-ish about vehicle appearance. With a black daily driver, even if my coating was still doing well after 2 years/42k miles, the car woulda needed to be re-done due to defects instilled over the course of those miles in a harsh world. A coating with a 5-7 longevity, even if it were accurate, is not something I personally would ever need though others may have different needs. Since the whole 'eleventy-billionH hardness' is pretty useless when discussing scratch resistance of a coating, the world will eventually take it's toll on the paint w/ respect to scratches, scuffs and other road-borne injuries.
As with anything, YMMV...just my experience.
