Logo designers are creative souls who need to be “in the zone” to do their best work. The best logo designer in the world will deliver mediocre work if she thinks she’s mediocre.
If you don’t have the patience to work through many revisions of your logo or the patience to allow the designer to take her time, delegate the task. That guy on your team who never gets upset. He’s the one. Have him deal with the logo designer. He will get far better results than you will.