@ LukeTW - I have no idea if it's making any difference or not, as I installed it from the start of the build. I am considering removing it though, as the fans are barely turning. I think that's probably partly to do with my wiring though, as I needed 2 extension cables to get it to my fan controller. I might bypass the controller 1st and see what happens.
Whether you have it as an intake or exhaust will depend on your setup. What I noticed is that my PSU below gives out very little heat, so the BS-08B should be able to draw in relatively cool air from outside and blow it onto the GTX, which IMHO is better than it competing against the GTX for airflow. If it sat higher than the GTX in the case, then I would say exhaust every time, but with it sitting below I can't help but think it is better suited as an intake. The problem I have with it though, as I said is it seems to be putting out very little air. Time to bypass the fan controller and see what happens before I ditch it.