Several times in my career i have played around with ImageMagick and have always found the documentation of its usage with PHP to be severely lacking. Or in most cases though the problem originates with the server.
One of the biggest problems with a WordPress site is optimizing its speed. If you use the popular plug-in for FireFox Yslow, or Google’s page speed they will always tell you to move the JavaScript to the footer in order to make your page load faster.
Ever wanted to know exactly how many times your browser is querying the server? Or how long it takes for you page to load? Even Yslow cannot detect these queries!