I have a all in one water cooling setup similar to that. It is a Kingwin Arctic Liquid setup. It used 2 rads, one with an 80mm fan and the other with a 70mm fan. (If you read my other thread it's where I stole the fan from.
It did the job, but it just didn't have enough flow to really be better than air. I would suspect the same could be said for that CoolIT system because it looks like it has 1/4" tubing. The CPU block also looks pretty thin which would also mean it doesn't flow a lot of liquid through it.
Another point is that the pump will probably make more noise than the 120mm fan does, so it's not as quiet as you might think.
From what I've seen with my kingwin unit it's best to leave the sub $100 price to air. If you really want a good liquid cooling system it's going to be closer to $200 to get 1/2" tubing and a good pump / radiator / block.