i use a sump on my 200 gallon tank.
I bought it second hand with my tank that was already prepared for it.
I love it, apart from a glass box in the middle and 2 inlet pipes that just break the surface there is nothing in my tank equipment wise.
You almost never have to clean it aswell!!
You can use what ever media you like aswell.
The only problem i had was getting my desired water flow, right now I'm running 2 Aquamax 2000 pond pumps which do a descent job producing a current.
it's also good for keeping bacteria alove for other tank, like at the moment i'ved closed down 1 of my tanks but the bio-media is ticking over in my sump!!