Still haven't even used Typescript. What's the draw?
There’s basically no extra effort to using typescript if you already have a build pipeline running. It’s not like using Java or Haskell where you’re drowning in type definitions.
TypeScript makes writing frontends easier and it makes writing Node-JS apps easier. It makes it easier to both read and write code.
> Just didn't feel worth the effort if you're building for throwawayability.
Now that's a legitimate point. If you're building for throwawayability, then TypeScript and FlowType are probably not worth your effort. For other people, modeling things with types helps them move faster even for throwawayability.
Personally, I tend to code first, use type inferencing first, and then annotate later. However, I also tend to use a lot of reflection as well to help me prototype things quicker. If I've found the types I've wanted after I've explored the domain space, I'll then annotate afterward to lock them in.
As with anything, YMMV.
If you've ever had to debug a misbehaving Knockout template just to find it was referencing a misspelled object property, you can appreciate how much cleaner TSX templating is.