title: coredata - save content as json string or nsdata
body: <p>In my iOS app I've got a server sending me json messages.
  I decode those json messages and built a custom object from.</p>
  
  <p>Amongst the json data I also get a property of custom objects which get decoded differently by different controllers, so I'd rather keep that information decoded / in raw format and not build a custom class from it. </p>
  
  <p>I wish to save the object and its custom data to a local database using coredata. I'm now contemplating the two alternatives. </p>
  
  <ol>
  <li>Saving the custom data as raw NSString property of larger object</li>
  <li>Saving the custom data as NSData property of larger object</li>
  </ol>
  
  <p>With which one should I go? What's the best practice here?</p>