I started using Sea Foam as a gas additive when I got the bike a couple of years ago on the advice of friends who have moat motors to maintain. I have been happy with it. When I overhauled my carbs over the holidays, I found them to be pretty clean, which I attribute to the Sea Foam. I also found it to be a good cleaner and used it to scrub the brown film off of the outside of the carbs. I've never had a fuel related problem and the rubber fuel lines don't seem to be cracking over time except at the ends where the rubber is nor exposed to the fuel.
The best testament I've heard came from an auto parts store owner who used to work on the Outer Banks of North Carolina. He said that his customers who owned commercial fishing boats would come into his store buy cases of the gallon size cans. They wouldn't be using the stuff if it work for them.
But if you plan on pouring it directly into the carbs to clean them, be prepared to jump on the bike and head to the highway or else you and your location will be enveloped in a huge, huge cloud of smoke coming out of the tail pipes.
John M