title: Storyboard segue is slow only the first time it is pressed
body: <p>I have a UINavigationController, and the Root View Controller contains a UITableView. In the storyboard, I attach a segue from the UITableViewCells to another UIViewController.</p>
  
  <p>When I'm on the Root View Controller and I tap a UITableViewCell it takes between 1 and 4 seconds to perform the segue to the other UIViewController. However, because this is all in a UINavigationController, I could go back to the Root View Controller. When I go back and try the segue again (from any cell), it happens instantly. It is only slow the first time I do the segue. Why is this?</p>
  
  <p>I'd post code, but this is all extremely vanilla stuff and it is slow even when my <code>viewDidLoad</code> method in the destination View Controller is empty. </p>