Softer tires are faster, more comfortable, and grippier.
I used to think that 100-125 psi was the ideal tire pressure. Faster. Less rolling resistance. Well, that’s not the case. Softer is not only more comfortable, but faster and grippier. The contact patch, the part of the tire in touch with the road, is actually smaller, improving the rolling resistance.
Check out this link to calculate the best tire pressure given your weight, tire width, and riding style.