Eheim makes one of the best filters in terms of build quality, reliability, pump longevity, noise, and mounting/set up hardware. This is all negated by the fact that their manuals are terrible and more so that their warranty department treats individual consumers pretty poorly. They make a wet/dry system which is an amazing machine; we had one on our 135 and the tank was fully cycled within about 3 weeks which is amazing for a tank of that size that wasn't seeded.
We didn't like have 10+ high dollar filters that a company wouldnt stand behind so we have been selling them and shifting to the Marineland Emperor Series and the HOT Magnum Series w/ biowheels as they provide good wet/dry filtration for the money. The Aquaclear filters have a better fit and finish than the Emperors, but lack a wet dry componenet. With that said, they are also a lot quieter and they do move a lot more water than the Marineland. We would up doing Marineland/Tetra/United Pet Group because their warranty department is great. Otherwise, we would have stayed with Eheim or gone with Hagen.