It works pretty well. I'm not crazy about it, but I don't have enough experience with other skimmers to be overly critical. It pulls out really dark and smelly skimmate, but it seems to need cleaning once a week or so. It gets about 3/4" in the bottom of the cup, and then the walls in the neck of the skimmer get too dirty, so the foam won't rise up any more. So off with the cup, clean the neck, and I'm up and running again. Is there any way that I can make it easier to get along with?
So I suppose I am a medium skimmer, but probably only for about threee days, and there are two of three days of no skimming in my system.