I'd advise against using shorttags, see Are PHP short tags acceptable to use? for more information on why.
Personally I don't mind mixing HTML and PHP like so
<a href="<?php echo $link;?>">link description</a>
As long as I have a code-editor with good syntax highlighting, I think this is pretty readable.
If you start echoing HTML with PHP then you lose all the advantages of syntax highlighting your HTML.
Another disadvantage of echoing HTML is the stuff with the quotes, the following is a lot less readable IMHO.
echo '<a href="'.$link.'">link description</a>';
The biggest advantage for me with simple echoing and simple looping in PHP and doing the rest in HTML is that indentation is consistent, which in the end improves readability/scannability.