Rodrigo M. reviewed Qualia Focus
The best one for me.
Good for focus and productivity
Effects are subtle, but consistent. I'd describe them as a general increase in clarity and ease of focus for about 4-6 hours after taking before steadily winding down with no noticeable crash.
Sustainable focus and energy all day
Good energy through out the day without the afternoon crash. I find a have better focus at work and can more easily follow through and complete what needs to be done.
Focus
My job requires me to get up at 3:30 a.m. and adding Focus has helped to get my work day started. It's also allowed me to cut down on the amount of coffee I normally drink in the morning.