Whitespace, Plugin, EE 2.0, Variable set and Logic

I am working on a plugin in EE2.0

It looks at the url and breaks it out and makes assumptions based on the data on the url segment. I then pass back a word:

try
{
    switch($this->_type)
    {
    case 'category':
        $this->return_data = trim($this->_type);
        break;
    case 'city':
        $this->return_data = 'city';
        break;
    case 'state':
        $this->return_data = 'state';
        break;
    default:
        throw new Exception('Invalid search type ' . $this->_type);
        break;
    }
}

...

In my template it starts with:

{preload_replace:controller="{exp:urlcheck}"}

If I output {controller} it displays the value I expect

I then want to test that value and based on it embed a specific template:

{if controller == "category"}
           {embed="/category"} 
      {if:elseif controller == "city"}
            {embed="/city"}  
      ...
      {/if}

It never seems to match. If I highlight the output of controller and paste it I will notice white space padded on the end. I tried to trim as you can see above but no luck.

Should I be able to test a preload_replace variable like I am, if not is there another solution?

Is this possibly a bug?

Thanks!