you fill your rig up with high quality (i.e. noctua) fans and run em at medium speeds (900rpm-1200rpm) you will find your rig stays plenty cool.
perhaps what matters more than the cooling method used, is the type of computer case that you have and cable management.
If you have a mid tower case, liquid cooling is probably a horrible idea and a waste because the airflow is bad, causing ambient temps to rise substantially. Even with some full towers, liquid cooling functions just as effectively as air. Keep in mind, design often matters more than the sheer size of any given case.
Note that I have no experience with liquid cooling, but do know enough about thermodynamics.
In my honest opinion, do not bother with liquid cooling unless you are overclocking more than 10%.
Lastly, what most people do not realize is that you could spend less money to simply upgrade your core components than you could trying to install a quality liquid cooling system to overclock.
-Blue