I highly recommend it. A gallon from fasco is around $100, we were able to do three 1648 hull bottoms. As long as you are not running up on gravel and sand or jumping beaver dams on a daily basis, it will last several seasons. Well, worth it, reducing friction while running mud/veggies. It even does some sealing on rivetted boats as well. There are other products, like "frog spit" but I can't speak for that. If you run clean water you don't need it. One thing, it is very slick, you must keep the boat tied to trailer until ready to launch or it will slide off the trailer on any incline- my friend found out the hard way.
The application did cause my boat to drift slightly on turns, like an airboat but you adjust to that and much better running in the marsh as well as making it easier to load/unload from the trailer.