In the article, he looks at what accelerators are, how they work, and some of the ones that are currently out there in the market:

• APC
• eAccelerator
• Zend Platform

With the ground rules established, he breaks out the analysis into a few different rounds/categories including: support/maintenance, the accelerator's actual performance (including the code they used) and the results he discovered (all graphed out), and, finally, how they handle file updates made to the system.

In the end, there just isn't one that's a clear winner. What it really boils down to is what kind of situation you're in - Zend's option is good if you can pay for everything, otherwise, you'd do well to go with eAccelerator.