i went to look at my local retailers data on filter machines and most moccamasters had a quite good but not perfect rate often around 1-3%, things to keep in mind are that its a local store so there isnt large amount of data so seeing rates of 0% or 10%+ were common but more interesting was the reviews that ultimately indicated that you basically want to get either a moccamaster or WMF, though many of the brands in that list are not sold here so cant comment on them