BTW, it will spit less bubbles after the other gasses are out of your CO2 reactor (if your using DIY CO2). Mine typicaly only spits noticably when getting over 3 BPS.
I think they work extreamly well @ 99% diffusion, but the negatives are, 2 more cords in the tank (Cord and Hose; not negative if if I put it in the sump ), and they can get plugged by leaves and debree when can hinder it's functionality.
now my bubble ladder...thats always getting messed up by leaves growing into it, snails climbing on it etc, at least this unit is enclosed.
One thing I REALLY don't like is that the power cord and CO2 Intake Hose are on opposite sides. For some reason this just really bothers me and makes the unit a little harder to position.