I purchased 2 brooks a B-17 special and a Flyer Special. They were the most comfortable saddles for long distance I had tried but i still had problems between 85 and 100 miles. Then I got a Selle An-atomica (without the slot). Now i am replacing both of my Brooks. The Selle has its issues (around the edges specifically) but it fit my sit bones better than the brooks does.

I think a brooks should be comfortable out of the box. It should get better with age. But if it still doesn't work after a season of riding I would look for something else.