There is a huge reason. The noctua nh d14 surpassed almost every single all in one water cooling solution while producing the least amount of noise. The heatsink is so effective you don't even need to run the fans at full speed. I use the ULNA adapter which i think runs the fans at 5 volts and i run an i7-980x at 4.2ghz and the cpu stays in the mid to high 60's and it is inaudible compared to the case fans and gpu fans. It basically removed 1 source of noise from your pc completely that's how good it is. The water coolers their fans are louder than noctuas and the pump itself that moves the water is louder.I don't understand why anyone uses the more expensive air cooling anymore. The closed loop water coolers work much better, don't have clearance issues, and are much easier to work with. The person building the machine just has to be sure to use a case that will work with the cooler. They're a little more expensive, but not that much. I've been using Corsair coolers with my last 4 builds. The H90 I used in my virtual trainer box was less expensive than the high end air coolers.