The cooling performance of the Seidon 240M is right up there with the better of the 240mm all-in-one units, this includes the Thermaltake Water 2.0 Extreme and the Corsair H100i. We love that Cooler Master stepped outside the box a little with their version of the AIO cooler. No longer do we have to look at the same two typical style head units we are accustomed to.
The fact that Cooler Master did not complicate things with a lot of wiring coming out of the head unit or needing to be connected to it was also a bit refreshing. This makes for a better looking install with potentially better case airflow. Granted, with eliminating the cables needed to go to a USB header, you miss out on have a dedicate AIO software suite like the Corsair and Thermaltake higher end models. We don’t see this as a big problem as many motherboard manufacturers make an application to allow you to adjust your fans from within Windows, or you can simply download a third party application like SpeedFan.
Even with the Seidon 240M performing well just as it is, you mustn't forget that there is still the option of adding two more 120mm fans to the unit to configure a push/pull setup. This should be good for another couple of degree drop in load temps.
The Seidon 240M is one of the best priced dual 120mm all-in-ones at under $105.