Thanks for your reply Ken. We're testing the 100 series. The 500 series appears to be a "hard finish" product, which is not what we want. Our deck contracts involve a 5-year maintenance program in which we return annually for 4 years after the initial restoration, so we're not so concerned about the length of durability of the product. At least not to the degree you would if no maintenance was being done. This possibly eliminates your issue with the "one coat coverage" results? However, our concern about the mildew resistance the product offers between maintenance is of great concern. Have you experienced issues with this at all? Although I am looking at other products, and would like to discuss them, local distribution and inventory levels are a major concern. I will give you a ring when I have a chance. Trying to get late season decks knocked out before the snow flies. It's been colder & wetter than normal here for the past month. Waaaayyyyy too early!!