The gasoline won't go bad as quickly, you won't have the corrosive effects of ethanol (though modern cars are designed to resist that), and you'll get a little better gas mileage.

The mandate to adulterate gasoline with ethanol took effect in the U.S. in 1992. Prior to that pure gasoline was the norm. Ethanol-laced gasoline has has no real benefit to the consumer, or really anyone except the farmers growing and selling corn used for this purpose.

I think this is covered in our FAQ

The benefit is that you get more power and fuel economy. The downside is that costs more. Much more than the benefit you get from it, so it's probably not worth the hassle.

Gasoline provides more energy when it burns than ethanol, so you get slightly more mileage and power. Since ethanol absorbs moisture from the air, ethanol-free gas will store better, and is less likely to gum up the fuel system, especially if it is a stored vehicle, e.g. boats and motorcycles in the winter.

Is it worth the extra cost? I just use fuel stabilizer for storage (Sta-Bil, but there are other good choices)

Here's some more info: https://carpartnews.com/ethanol-free-gas/

And, Scotty's take:

I only use ethanol free for my emergency 5 gallon gas tank for my generator. I use sta bil on it too, and it won't go bad nearly as fast as with ethanol. Also, better on a carburetor, so I hear.