If only one Matrix block show this, for more then one block show that
Thanks to Brad for asking me a question above, it made me realize I was checking for matrix fields and not the matrix block. My code is now working that I am checking for the correct element on the page.  

Revised code:

{% if entry.modelIds|length == 1 %}
     I am link - {{block.modelId}} &lt;br&gt;
{% else %}
     Not a Link - {{block.modelId}}&lt;br&gt;
{% endif %}


Thanks Brad for the help!