They are the same but the second one is great if you have MVC in your code and don't want to have a lot of echos in your code. For example, in my .phtml files (Zend Framework) I will write something like this:
<?php if($this->value): ?>
Hello
<?php elseif($this->asd): ?>
Your name is: <?= $this->name ?>
<?php else: ?>
You don't have a name.
<?php endif; ?>
I personally really hate the alternate syntax. One nice thing about the braces is that most IDEs, vim, etc all have bracket highlighting. In my text editor I can double click a brace and it will highlight the whole chunk so I can see where it ends and begins very easily.
I don't know of a single editor that can highlight endif, endforeach, etc.