You're seriously asking if we'd choose AC PLH in transcontinental business class over UA narrow-body?

Unless you're buying revenue tickets and are at 98k PQM and 2 UA segments, there is absolutely no reason to take the UA flights.

AC 319 is a bigger seat than UA 737, AC catering is better, and in my experience, AC service is better.

Switch the 319 for a 333 and you get seat++ and catering++.