I'm just wondering your opinion about losing fat, the fat burning zone vs higher intensity workouts.

I've always been taught that 65% HRR allows optimum fat burning, more useful than higher intensity exercises.
Reading this article there's obviously a different stance:

http://scienceblogs.com/obesitypanac...burning_zo.php

whilst you may burn a higher % of fat from lower intenisty exercises, the increased total calories burnt through higher intensity exercises beats that.

What's your take on it?

Would you recommend clients looking for fat loss train at the 65% HRZ or just push them harder to expend more calories in a shorter time?