title: CoreFoundation vs Foundation
body: <p>In iPhone development, speed is of the essence. Does anyone know if there is a speed difference between using a CoreFoundation type (like CFMutableDictionaryRef) versus a Foundation type (its counterpart, NSMutableDictionary).</p>
  
  <p>I would think manipulating the CF type would be faster as it doesnt have to throw around ObjC runtime messages, is this an unfounded assumption, has anyone actually looked in to this?</p>