I've used Startron since it was Soltron and hard to find, about 6
years. When I first got the boat, I shocked the tanks per their
directions,then had the fuel polished. I've used it ever since. I had
a small leak a couple of years ago, and we opened up the tank to clean
it out and line it with aircraft fuel tank sealant. The inside of the
tank was pretty darned clean. This is a steel tank on a 20 year old
trawler. There was a little bit of black stuff, maybe 1/8" thick on
the very bottom, and some sediment which was mostly rust falling off
the top of the tank, where the fuel doesn't hardly ever slosh up and
cover. I've been very impressed with Startron, and continue to use and
recommend it. The PRI stuff at least looks good too, but I've never
tried it personally. I do have to wonder about someone who spends all
that time/effort bashing their competition though. If your product is
so good, just sell it on it's merits.