I have used one for benching. It cools well. I use the EX2-1055 3 fan model, but the 755 model does well at about 590watt of cooling.
That said, aestheically a plumbed system in your case is nicer. It looks better and is all self contained, if that matters.
From a pure cooling point of view, however, both the 1055 (900watts) and 755 (590watts) are hard to beat in cooling performance for a 360 or 240 configuation. You are always getting cool ambient air to cool your radiator and not dumping any warm air into your case.
So it depends on your priorities.