Head to head, the H50 and ECO are very similar, but there are many differences that make me still lean one way versus the other. Temperatures are almost a dead heat when the processor is loaded, so I award no favorable points to either cooler on this subject. I feel the same way about the noise levels. While the Corsair does edge out the CoolIT solution out of the box, we all know that will last for like the first week, maybe, until "tinkering" begins. So with those out of the way and still no clear leader, I have to go deeper to make an actual decision as to which I would actually buy with my hard earned dollars.
First off, I will go to the most obvious components that the everyday user will have to deal with just to get either product in your chassis. Starting with the most fundamental, let's go with the mounting. The Corsair offers a ring with keys on tabs that lock the ring into the head unit. Simply slide the ring over the unit using the keyways to pass the ring over the "latches", then turn the ring slightly to align the tabs into the headunit. Easy, right? - Not exactly, the rest of the hardware is where things get tricky.
Adding the correct clips, using the right screws for said clips and any mistake in these steps adds time for tearing all your work back down. Lastly, I found the nuts to the backing plate to be loose and with everything going on up top I dropped those nuts uncountable times in the assembly process. In contrast, here is where the ECO steps leaps and bounds over the Corsair H50. The ECO is simple! Pick the AMD or Intel mounts, four screws to swap out the legs (AMD only, ships with Intel mounted), add a back plate and screw in some thumbscrews. How tough is that?
Beyond that, I really liked the fact that even during load testing of the ECO, the head unit never seemed to get warm. I mean it was warm, but not where I would consider it oddly warm, or near hot. I can't say the same for my H50. During even idle testing I could feel that the pump was adding plenty of heat to the loop, not something I particularly want and something CoolIT found a solution for.
Other than that, the CoolIT just feels beefier, or better built. In the end I am torn. I can't pick a winner based on performance, so I have to go with ease of use and compatibility and that makes me want to spend my money in that direction. To be fair, with all the fundamentals being equal, minus the head unit and mounting, it is a dead draw. You already know what my money is going on, but based on local availability I won't steer you from grabbing a Corsair H50, as it does its intended job admirably.