Ferris, Their biplanes aren't bad...somewhat basic, but that's a good datum line to start from.
Their helicopters are very basic...good for beginners(i.e. Cobra, Huey, and Jolly Green Giant).
Don't know about the others....Overall I'd say they are dated and basic kits....that can be good or bad
depending on your outlook. Sorry I can't be of more help. Bill