Its probably about the equivalent of Sta-Bil. It will help prevent the fuel from oxidizing in the tank during long-term storage (months), but it won't do anything to reduce possible deterioration of ethanol-sensitive rubber components, if any, in the system.
I've seen no effects at all from E-10 on any of my vintage cars, but then I was prepared ahead of time. I'd been using fuel injection hose instead of ordinary fuel line for years, and all of mine have Carter carbs with no rubber diaphragms and very few rubber parts at all.