I tried this program and Amphetamine and Caffiene. I like Anti Sleep best, especially for the new MacBooks with Haswell chips that no longer have a 'Never Sleep' option under Power Preferences. Here's what I like in Anti Sleep:
1) has a auto launch/auto activate on system startup option, great for remote systems, like a laptop, that need to be always on for access. No human needed to activate.
2) Has options to only activate when powered by AC, versus battery. Again, great for laptops
I provide remote assistance to family. When they need me to look at something on their system, I just need to tell them turn on the laptop, plug it in, leave the lid up. I can then log in anytime thereafter, even late night. I set options auto launch/activate at startup, activate only when AC is on, and stay awake indefinitely.