I've been using one for close to two years now. Doesn't mean I know anything about them though. What's your question?
I have to clean the pump and venturis every couple of weeks. It does not take much to clog the small openings. The pump gets cleaned too and I seem to go through too many impellors. I also periodically replace all of the tubing. I keep the return pipe as high as it can go so that the water level in the skimmer is almost up to the O-ring in the collection cup.