title: Difference between unwrapObservable and ()
body: <p>Is there an actual difference between:</p>
  
  <pre><code>y = ko.observable("value");
  x = ko.utils.unwrapObservable(y);
  </code></pre>
  
  <p>and:</p>
  
  <pre><code>y = ko.observable("value");
  x = y();
  </code></pre>
  
  <p>Should I prefer one of the above and why?</p>