Sourcenstalling the Kühler is easier than most other compact liquid coolers due to the flexibility and length of its soft rubber hoses. The "universal" Intel backplate (on AMD systems, the stock motherboard backplate is used) keeps the parts count (and price) down, and while I prefer the more robust mounting system design of Asetek's original systems, the current mounting system certainly doesn't seem to affect the performance.
The performance of the Antec Kühler H20 620 was excellent, exceeding that of every other water cooler I've tested and encroaching on the performance range of the very best air coolers. The stock fan is quiet at full speed and very quiet at low speed. I tried replacing it with an 88CFM fan, which generated more perceived air flow and certainly more noise, but actually slightly less performance. It's not clear if just any 3-pin fan will work with Antec's unique fan speed control system, and it would be nice to see some information from Antec on this