His face movements were excellent, they were much like Nixon's real mannerisms. The problem was the edges of his face were pretty bad. The voice was also bad, with obvious ghosting and glitches.
That said as someone else pointed out this was done in 2019. If this was made today the face edges would be much better and audio clearer. I'd love to see this remade now.
It's interesting compare it to a real speech. Nixon has weird mannerisms but the deep fake feels like a disconnect between the speech and the words. It's tough to describe how my brain differentiates weird mannerisms and looking odd in a more fundamental way. In the deep fake when he reads off the names of the astronauts his shakes in this weird way that mind immediately screams that's not human, but nothing feels like that in the checkers speech.
That said as someone else pointed out this was done in 2019. If this was made today the face edges would be much better and audio clearer. I'd love to see this remade now.