What size tank do you have? I was looking at the 6055 actually. It can range from like 396gph-1,188gph. Has a dial to change the flow.
I have a Hydor Koralia 750gph that I recently bought. It works pretty well for my current setup. I have 3 smaller ones (550gph). Those are all in my 46gal. Once I get my 135gal up, I don't really want to use as many. So looking at those Tunze x 2 and see how that will move the water around. I may use some smaller ones in conjunction just to get some possible harder to reach areas. Won't know until I get it aquascaped.