Watercooling Pros and Cons?

I prefer Koolance, as I have had Koolance systems in the past. I don't work for them or get any money from them. They did get some money from me though!

Water cooling is usually more efficient than air cooling and can be applied directly to the heat source. So, you can place mini radiators on the CPU, GPU, hard drives, etc. to wick out the heat.

Water cooling is also quieter, since you can use fewer fans. You still want good airflow in the case, and many water cooled cases use fans to cool the water but the hottest elements of your computer are being water cooled, so you don't need a bunch of loud monster fans.

Water cooling requires you to know what you are doing because you can short out your computer. You are putting liquid in your case full of electronics, after all.

Water cooling requires some maintenance. Like a car, you want to change out the coolant regularly to ensure it maintains high heat transfer and avoids overheating your components. A flush about every six months is recommended. I usually ran a mix of 4 water to 1 coolant that was sold with the case and was probably not too much different than car antifreeze. Too strong and you will damage the tubing, not strong enough and you won't move enough heat. Flushing has to be done carefully as there are of course liquids next to electronics.

Finally, there are some crazy things you can do with case mods and water cooling. You can use cooling fluids with dyes or that glow in UV case lighting for a crazy effect. If you have a case window you can see the water cooling pipes and it gives a very cool effect even without lighting and dyes. It does fill the case up, so you want to account for that with a large case.

Watercooled computers are heavier, since they have several pounds of water, radiative cooling plates, tubing, etc. in them.

Y!A is the worst possible location for getting water cooling advice...

ask the same question at tom's hardware