removable percs are a pain in the ass, trust me your better off with something single or double percolated anything more than that is overkill since it induces too much drag into the bong, unless you like stale smoke.
Percolaters diffuse the smoke and break down the volume of the smoke bubbles so it cools faster and more efficiently.
And yes the idea of it being removable is so that it can not only be easier to clean but at the same time you can use it perced or not.