The Plane Plastics parts are generally much thicker and sturdier than factory plastic. That said, they generally require more trial and fitting than factory parts. Not complicated, just requires time and patience. I've used both factory and PP replacement plastic cabin parts on my C172. The Cessna factory parts fit with minimum trimming/fitting. The PP parts required perhaps an hour of trimming, sanding/filing etc, but will not turn to eggshell in 20 years either. Plane Plastics has some "how to" videos on their web site which give you an idea. Many were done by a good friend of mine.