works well
I have one on my 1985 Westerbeke 21a. It works quite well but I don't depend on it. I change my fuel filter every 200 hrs or annually, which ever comes first. As for the quality of the fuel, I belive keeping it algee free in the first place is very important. On my guage, the average vacc. pressure is 2-4 (not sure if it is measured in mm/Hg, PSI or cc/H2O). I once had it measure as high as 6. Although I don't refer to it much I like the idea of having that information available to me when I do have a filter question. And if I do have a question about my filters I just change them. I look at fuel filters like reefing the sails, if you are thinking about doing it than just go ahead and do it. Sure beats Sea Tow dragging me in, again.