Which is the most performant way of overriding views field output This question sureley can only be answered by people with some drupal experience.
As I have quite different and complex views, which I need to control totally, I need to come to a design decision. Which way has the highest performance putting out view content?


Define the fields in the Views UI, don't output them and use them in custom text? Like described here: http://highrockmedia.com/blog/rewriting-drupal-views-output-custom-theming-css
Provide a views-view-field--field-machine-name-of-field.tpl, get the $row['_field_data']['nid']['entity']->{'field_machine_name'} and iterate over its contents?
Another or better way of which I'm not aware off?


Example, of how a result could look like:

&lt;div itemscope itemtype="http://schema.org/Product"&gt;
  &lt;img itemprop="image" src="dell-30in-lcd.jpg" /&gt;
  &lt;span itemprop="name"&gt;Dell UltraSharp 30" LCD Monitor&lt;/span&gt;
  &lt;div itemprop="aggregateRating"
    itemscope itemtype="http://schema.org/AggregateRating"&gt;
    &lt;span itemprop="ratingValue"&gt;87&lt;/span&gt;
    out of &lt;span itemprop="bestRating"&gt;100&lt;/span&gt;
    based on &lt;span itemprop="ratingCount"&gt;24&lt;/span&gt; user ratings
  &lt;/div&gt;
  &lt;div itemprop="offers" itemscope itemtype="http://schema.org/AggregateOffer"&gt;
    &lt;span itemprop="lowPrice"&gt;$1250&lt;/span&gt;
    to &lt;span itemprop="highPrice"&gt;$1495&lt;/span&gt;
    from &lt;span itemprop="offerCount"&gt;8&lt;/span&gt; sellers
  Sellers:
  &lt;div itemprop="offers" itemscope itemtype="http://schema.org/Offer"&gt;
    &lt;a itemprop="url" href="save-a-lot-monitors.com/dell-30.html"&gt;
     Save A Lot Monitors - $1250&lt;/a&gt;
  &lt;/div&gt;
  &lt;div itemprop="offers" itemscope itemtype="http://schema.org/Offer"&gt;
    &lt;a itemprop="url" href="jondoe-gadgets.com/dell-30.html"&gt;Jon Doe's Gadgets - $1350&lt;/a&gt;
  &lt;/div&gt;
&lt;/div&gt;
I would go for Template based solution for the sake of maintainability and flexibility. For example, if you are using the same field in two different views, you can use a .tpl file that applies to all views that have that field. But if you depend on Views UI, you will have to configure each field in every view separately which may complicate things in the long run. Also, the fewer access to database to retrieve configuration the better.