I tend to think that having an extra outlet affects the internal air pressure, especially if you are slowing down the case fan as much as possible. This is an important factor when using a passively cooled GPU, I needed to keep the airflow nice and even over the cooling fins. I also feel that any warm air from the case may have caused the temperature controlled fan in the PSU to spin higher than necessary which raises the noise level even though I changed it for a quieter fan, I wanted to reduce fan noise to an absolute minimum. As you well know, air coming from the GPU can be very warm so allowing it to go through the PSU could be a bad idea if you want it to be quiet. With this case I have a system that is no louder than my own breathing and that is absolutely crucial to me and it is due to the layout and features that it has. It also runs very cool indeed, I don't think I could have achieved such a small, neat, quiet and fast system with any other case of this size.
It's horses for courses really, you only have to look at the wide variety of systems that people have built into this case to see how versatile it is but it does have it's limitations and so not perfect for everyone.
Edited by Indigo340 - 5/31/13 at 12:23pm