I have a Corsair Obsidian 750d, but I hate it. I honestly don't know why because it's a good case, I just find it unattractive I guess. So yesterday I went and got a 760T which just looks a lot better to me. I'm in the process of moving all my components out of the 750D and into the 760T. My question is about the top cover. Does it need to be off when using a 240mm radiator on the top with 4 fans in push/pull. Front 2 140mm fans are intake, as well as a 120mm bottom intake. Rear 140mm fan will exhaust and so will the top radiators fans. My 2 MSI GTX 980's are blowers and blow the air right out the back of the case so no added heat entering case. Not sure if corsair designed the cover and case with enough gap for air to excape, or air hits the top cover and then finds it's way out of the top rear vent. It sure looks kind of funny without the cover on.