title: Use of custom delegate vs NSNotification vs NSUserDefaults state
body: <p>In my app I'm using NSUserDefaults to give a state then performing operations based on that state. In other places I'm using NSNotification-s to fire methods in other classes. I feel like for one example specifically it would be better to use a custom delegate. </p>
  
  <p>What are the benefits and drawbacks to using NSNotification vs a custom delegate vs what I'm doing now with NSUserDefaults?</p>
  
  <p>My question specifically intends to address any performance or potential issues between using NSUserDefaults to give state compared with simply calling methods using either protocols or NSNotificationCenter.</p>