I have never used it and never will. I have seen light fixtures dripping water, mold as far as the eye can see all from a non-breathable synthetic. Now I know these roofs were under ventilated and slightly under insulated. Yes there were bathroom exhaust vents that were not hooked up properly with adapters and clamps and basically stapled and pointing in the direction of the exhaust opening. Many things were wrong with these roofs and needed to be addressed.
Synthetics are great if your leaving them exposed to UV. I've had titanium over my chicken coop for about 14 months, maybe longer. I really need to split some shakes!
sorry started and got interrupted before I could finish the post..... to be continued.