I can attest to a better mood while on Soylent. Even under pressure I feel more calm, although I am still a smart ass.
Also I have not had any crashes since I have been on Soylent. I have gotten sleepy though, but without any energy crash. Meaning that if I decided not to sleep then I had plenty of energy to continue what I was doing.
I still have a grumbling in my stomach while on Soylent. So I have been subtracting one thing a day to see what it is. So far I have eliminated Sulfur, Salt, Whey Protein, Vitamins, Calcium, Magnesium, Nestle Chocolate Quick, Jolly Ranchers, and my Egg / Milk protein.
The only things left for me to skip are Choline, Whole Oats, Potassium, Iron, maltodextrin and water.
Thus far none of the things that I have removed from my recipe for a day have affected my mood. Although the taste and how satiated I get while on Soylent have suffered immensely.