The 5 stars are also of the effort has Swiftech as much on the quality of the product, The radiator him while copper / brass provides a better thermal dissipation compared to other AIO that they are generally Aluminium.
The radiator has a dedicated tank which allows to fill or change the fluid! and even if you have air bubbles in the circuit (this happened to me) you could hunt by opening the tank and filling a little more liquid. (Before doing this procedure please move slowly in all directions in order to move the air bubble).
Here I hope that my opinion will be useful to you :)