Do you have a choice, or is this just an academic question?Would it make more sense to pay into deferred annuities rather than into the SS fund ? I have paid the maximum SS 'tax' since I have been working in the US for the last 10 years, and still my projected benefit when I reach 62 is only about $1k.
SS gives you some other useful benefits besides retirement, and I assume you are also paying into Medicare so you'll also qualify for those benefits at some point.
If I were paying the top SS tax and had a way to opt out of it, I would look for cheaper ways to buy the same protection.