Storyboard Segues initially seem like a pretty cool way to construct interfaces using minimal glue code. But actually, nibs already supported this concept in a much more flexible way.
Certainly, a Storyboard lets you bind a button action up to display a view controller with no code, but in practice you will usually want to pass some data to the new controller, depending on which button you used to get there, and this means implementing the -prepareForSegue:sender: method, which rapidly becomes a giant if/elseif statement of doom, negating most of the benefit of the codeless segue:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([segue.identifier isEqualToString:@"modalSegue"])
{
ModalViewController *controller = (ModalViewController *)segue.destination;
controller.someProperty = someValue;