Have been using the spread operator via Babel for several months now. It's definitely convenient - saving me from writing several extra lines of code.

I worry that spread operators make code less readable. You really have to squint and think more when confronted with one.

They also make your code less understandable to a beginner, or people coming from other languages.

One of my favorite ways to use them:

  const foo = {};
  if (bar) {
    foo.bar = bar;
  }

Turns into:

  const foo = {
    ...bar && {bar},
  };