I've just been pricing some itineraries at www.ual.com and find that it no longer tells you "we found lower fares using alternate (they mean alternative) flights" nor invites you to "consider these low fare options" after you've selected some flights. It just goes straight to ticketing those flights.
www.itn.com (with its clumsy Amex skin) still provides the additional information. I find it very useful for gaining insight into alternative routings and carriers.