I have over 5 CMP Planes .I just bought another one (this plane thanks you guys ).
My first CMP was the hellcat .The best way to describe the fuse is called "tin-canning" its the ability to flex the fuse in when not supported by braces .Based on the lower end materials being used this is where you get the easier cracks and paint chips .
I learned years ago that If I wanted my CMP P40 to last longer , I need to add a light weight material inside the fuse at the bigget areas of tin-canned effect .
THat is when I discovered -flightskin -, you can use simply CA or very little 5 min expoxy and add few sheets to the most prown areas in the fuse of flex.You would be amazed on how the fuse becomes rock solid by adding this product that takes all of 2 miniutes to apply .
I now use it to strength flaps , servos screw areas ect , its amazing modeling product .
I was going to try to sheet an open wing but I did not like the feel and opted against it .

A month ago I also got my first KMP corsair , personally I cant tell if the fuse is made of better materals or not because as far as flex its the same in open areas as the CMPs .
THe inside does appear thicker , so I have to test it as Steve suggested . I know the center section of the KMP corsair wing is composite and absoluet top of the line rock solid quality .

One last note , I found and others as well that clear coating the CMPs before the first flight can have the paint last much longer then not useing a coat .
The FW190 I am working on now will get clear coat , but I need to use some good fiberglass filler when the detailing will begin .THis plane was chipping out of the box so I sanded any areas of chip away in order to start fresh .
The quality of the glass appear to be ok , its the ability for the paing to ahear to the flex that can happen under normal load.