Should I use immutable collections in Scala.js
<p>As I understand it, in scala.js the <code>js.Array</code> is equivalent to <code>mutable.Seq</code>. If I convert it to immutable collections like <code>List</code> and <code>Vector</code>, would it impact performance significantly in the browser?</p>

<p>What's the rule-of-thumb / best-practice on using immutables in scala.js?</p>