I have a front intake, two side panel intakes, and two top exhausts in my case. I removed the bottom intake due to the restriction of intake air. The side panel intakes are usually off and I don't think I would need them until I add a second GPU. The front intake and top exhausts are constantly running, along with my CPU cooler and GPU.
I'm replacing the front intake fan with a quieter one to bring the noise down, and I expect it to have less airflow. But I think the front intake fan is just mostly cooling the drive cage, so I'm not too concerned about the airflow as long as it's moving. I think this is the optimal fan configuration for my case, but I would love to get some fresh air onto the GPU, since it uses a reference design and is dependent on the dead air surrounding the blower fan.
I'm actually really concerned about noise because my computer is on my desk about 2 feet away. The fan configuration I have right now is pretty quiet but the front intake can makes too much noise. The AF120 fans are nice but I was thinking of getting Scythe Gentle Typhoons, I hear those are top notch as well?