I saw the performance, too, last Sunday. I thought they were fantastic. I especially loved hearing the Brahms "Haydn Variations" in Brahms' own two-piano arrangement. La Valse and the 2nd Rachmaninoff were performed with bravura, as was the Lutaslowski "Paganini Variations," a true show-off piece.
Argerich is 63-64 years old (born in 1941). So yes, she's aged! Look at a photo of Freire from 25 years ago if you want to see aging!
Topic: Argerich