We're pleased to announce that Javascript coding is now available in the latest Construct update r157 ! See our last blog Introducing Javascript coding in Const...
I have both and you're absolutely right Ashley. The only real flaw of C3 is the impossibility of exporting on nintendo switch, which at the moment, for a developer, is a considerable market loss. Both systems have their own pros and cons, the fact of being able to use Javascript is definitely an important plus, unlike gml which, however powerful, is limited to gamemaker only.
You can export for Switch via C3 to Chowdren