The problem with having the cooler in the back is that it will now be pulling hot air from in the case to push through the radiator before leaving the case.
If it is installed in the top of the case (as it totally should be), then it can pull in cool air directly to the radiator.
Additionally, the case comes with a rear fan where the H60 is currently installed, which is used for exhaust. I have no idea what they did with that fan, but that's why it's normally set up in this manner.
Generally, the only time people put radiators in the back of the case is when they don't have other options.
If it is installed in the top of the case (as it totally should be), then it can pull in cool air directly to the radiator.
Additionally, the case comes with a rear fan where the H60 is currently installed, which is used for exhaust. I have no idea what they did with that fan, but that's why it's normally set up in this manner.
Generally, the only time people put radiators in the back of the case is when they don't have other options.