It definitely has a very strong and noticeable effect. I feel very focused throughout the day in fact the effect is so strong is may be a little too strong, I took 1 pill at noon and was not able to fall asleep until 5 in the morning that night, I also felt a mild sense of paranoia as I worked through the day - a feeling that I needed to get more stuff done faster, but I couldn't really pinpoint a reason why it would be so pressing. I do not think it would be great for your typical social situation, I feel a little too direct and pointed for a relaxed conversation. I also had a dry mouth that day and the next.
But if you have a large amount of work that needs to get done in a small time period, like a day, and want to make sure you have a mental boost to go into zombie mood and get everything done then this pill will probably be a good solution for you. But I would not be interested in taking it every day.