Ethanol Free vs Ethanol Gas: Does it affect performance

[Ciao]

I have a 2001 Porche Boxster S and am curious if anyone has performed a non-scientific study of the difference in performance of Ethanol vs Non-Ethanol gas? I understand Ethanol gas is better for older vehicles. As we approach winter here in America, I am going to top-off with Ethanol: it stores better during hybernation (winter months) because it doesn't gunk up the fuel system or absorb water. Ethanol is getting harder to find anymore and is a bit more expensive than Premium fuel

Thoughts?