Even though I already knew how to install it, the installation instructions were terrible.

The software was terrible. I could not even change the colour of the pump LED. Luckily, NZXT had just posted a beta of their next software to dropbox.com 42 hours BEFORE I hit the technical support forum, which solved the problem.

And, the pump is already making noises. I can hear it grinding from across the room in bed.

NOT impressed.

Phenomenal performance for an AIO, at 4.5Ghz on all 6 cores for multiple days with power management allowing all 6 to run max speed non-stop, the Kraken X61 kept idle temps in the 40s C and max temp under stress testing at 80C.

this is my first all in one cooler.

i found it easy to install . the CAM software that operates the system i found easy to use.

just running normally the temps sit around 15'c

underload it has gone up to about 55'c

the computer sit on top of my desk and has unrestricted airflow

Overall very pleased so far. Probably on par with high end air coolers, but definitely no custom loop competition. Five stars because I find it hard to imagine a similar AIO performing better to any large degree, but I have not personally tested any others.

Works pretty well, but as with the grid+, the software kinda sucks.

Although this may not be the most popular choice for an IAO, I really like it, and it cools with the might of a thousand angry snowmen. Unfortunately, the installation was... only just acceptable. I watched an installation guide on youtube that was absolutely no help at all (I won't name names), and even NZXT's own youtube instruction video just glossed over the part I was stuck on (coincidentally, the reason I was stuck was because of faulty instructions from the first video). But it was over quickly and it was all worth it. Matched perfectly with the Noctua fans. The CAM software is very good, actually. I like it; I'm not sure what everyone else is going on about. It's good looking and easy to use now (there was probably an update). There is even a handy dandy FPS meter which is fully customizable to display whatever you want (e.g. RAM usage, VRAM usage, CPU/GPU temps and load, and obviously FPS with lows, averages, and highs). As a side note, there were a few bent fins on the radiator itself out of the box D': This sort of upset me but I'm sure the performance is not really affected. Sorta gives a dirty look at NZXT's quality control though.

A very quiet cooler. Not compatible with the Zalman Z11 Neo case without some modifications to the case (see my Dark Knight Build).

Beautiful cooler, wish it would be in form factor with the case, but besides that, great and worth it more than the h110i gt

The NZXT Kraken X61 is a fantastic cooler - easy to assemble, remarkably powerful, and quiet (if you want it to be). So why not 5 stars? Honestly - NZXT's documentation and packaging leaves a lot to be desired. This is a premium product; it deserves a lot more than a flimsy cardboard holder and a poorly-printed instruction sheet. Thankfully, the online instructions are much better and the CAM software is working beautifully for me.

Excellent cooler. It does it's job keeping either my FX9590 or my R9 290x very cool even under max load for extended periods. The variable speed pump and fan are very nice and keep the unit barely audible when not stressed (ie internet browsing or youtube viewing.) The LED is a nice touch, but I wish you had finer control over it or at least more options for color cycle patterns.