From what I've heard based on others' posts, it's incredibly varying in its results. Some guys feel a noticeable difference in the bump, others do not. I'd recommend (if it's something you're considering) bumping it up for a few days and if there's no noticeable difference, drop it back down and you'll know. And if it is a noticeable difference, you decide if it's enough to make it worth cutting your overall uses from the bottle in half.
Good luck!