title: Performance hit incurred using NSMutableDictionary vs. NSMutableArray>
body: <p>I am considering using an NSMutableDictionary in place of my current NSMutableArray. This is primarily for KVC/KVO reasons. The collection will undergo heavy mutation within the inner loop of my drawing method. Can I expect to incur a significant performance hit if I go ahead with this replacement?</p>
  
  <p>Cheers,
  Doug</p>