Questions about Xcode6 Segue, no solution!

The segue of Xcode6 has changed,

About the first 3 options, never too clear, I test the results are as follows, simply to connect a few viewcontroller, whether with show, or showdetail, or present modally, The result is a controller that pops up from bottom to top, and when navigation controller nesting is used, both show and showdetail result in push effects! What difference does it really have?

Attached to the official documentation:

Address https://developer.apple.com/library/ios/recipes/xcode_help-IB_storyboard/chapters/StoryboardSegue.html

Questions about Xcode6 Segue, no solution!