He really didn't look good. He only completed 55% of his passes, threw a horrible red zone pick late in a close game, and his passer rating gets any QB cut.
The game was close because the defense and special teams had their best performance of the season. Had they played like they did most of the time that's a 38-10 rout and no one is lamenting the 8th-year journeyman bum Gilbert.
That said, Rush has even less experience and looks like even more of a bum. May God be with Dak Prescott.