The dependability of any coating is greatly based on the prepping the surface properly thats being coated. The other most important factor is how much that coating is exposed to the elements and chemicals used for cleaning. I've been ceramic coating airplanes since 2010. Early coatings were very difficult to apply and weren't very durable. Modern coatings are much easier to apply and much more durable. A professional grade coating will definitely last much longer and be more durable than a consumer grade coating when applied to a properly prepped surface.
We actually use coatings now that are true 4 year or true 8 year coatings. They are guaranteed to last that long or longer without any maintenance. Most other coatings will only last as long as they claim if maintained according to the manufacturers standards. It's the only coating I've ever used that's extremely scratch resistant and also resists bug etching.
For an aircraft the size of a Mooney our prices start at between $2200 and $2700 (depending on model and how bad the paint is) with a 4 year coating. Add another $400 for the 8 year coating. Price may increase based on the amount of time needed to paint correct and polish the aircraft. Paint that is in poor shape would add a little to the cost. If we fly to your location fuel and hotel expenses would be added to the cost. Expect for your aircraft to be down for at least 2-3 days for the process to be complete. If any of you are interested in our process I'd be happy to send you a message with all the details.
Check out our work at: https://www.facebook.com/superioraircraftdetail