I was hoping for better Typescript support for typing properties, since that is where 90% of our type errors occur. But it seems like you still have to specify the types manually. The example from the manual:

  const Component = defineComponent({
    props: {
      name: String,
      success: { type: String },
      callback: {
        type: Function as PropType<() => void>
      },
      message: {
        type: Object as PropType<ComplexMessage>,
        required: true,
        validator(message: ComplexMessage) {
          return !!message.title
        }
      }
    }
  })

Contrast this with React where this would be something like this (I think; I've never used React):

  interface Props {
    name: string;
    success: string;
    callback: () => void;
    message: ComplexMessage;
  }

  export default class Component extends React.Component<Props> {
    ...

Quite disappointing. Maybe not that surprising given Evan said he only started using Typescript very recently, and many beginner Javascript developers don't realise that they should really be using Typescript (fortunately Evan isn't one of them). I would recommend still avoiding Vue for this reason alone.