Now that the filter has been running for almost two weeks I wanted to update the thread.
The simplest, neatest way I've found to service the filter is to pull the intake and spraybar out of the tank while leaving them connected to the filter. If you're careful you can remove everything without spilling any water. If you try to disconnect the hoses to avoid removing the lines from the tank you will definitely spill water. This is the difficult part of the process. Once the filter is removed it is a breeze to open and clean.
Finding a simple way to service the filter was essential because it needs to be serviced rather often. The heavy load of debris produced by a planted tank clogs the sponge in just a couple days. I need to clean it at least twice a week to keep it flowing. If I forget, the pump sits there running without circulating any water.
I still like this filter. Design flaws aside, it does the job. It's just not suited to be the primary mechanical filter on a heavily planted tank. It would be perfect for a bare quarantine tank or running in a sump as a chemical/biological filter. But I would not use it again on a regular tank.
It is tempting to think it might work on a smaller tank. But then I'd be worried about the current it creates. It creates enough current in our ten-gallon tank to annoy our betta. In a smaller tank it would be even worse. Although that might be just what some fish want.
To sum up; if you use this filter on a ten-gallon or bigger planted tank be prepared to clean it every two to three days. If you just want to add biological/chemical filtration to a tank, throw a pre-filter on the inlet and you'll be fine. I would not hesitate to use this filter again. I'd just make sure I used it within it's limits.