Let's try some math.
18 seats behind Door 2 on the Polaris 772 at $1,500 is $27,000. Is $1,500 a high or low average for something like IAH-HNL?
$27,000 divided by the 72 E+/Y seats that fit into the same space comes out to $385 per ticket. I'm not sure if that's a high or low average price.
I wonder how many would be paying $1500 on a 48 seat Polaris flight to/from HNL and the mainland?
HI is heavily vacationers who usually are looking for Y services and many times take children along. I'll bet UA would have to offer lower priced cash upgrade opportunities or take FF mile for a lot of those seats.
The same applies to heavy TATL markets that rely on vacationers, Spain especially.
I like the 24Polaris or Diamond idea with diamond allowing couples an opportunity to fly together. Only 12 of 50 Polaris seats on the 772 are "together" - another 12 have a sliding window, but the seats are far apart and angle away from each other. Between Door 1 and 2, there are 8 together seats of 32.
It maybe should be noted the 767 has zero couple seats as the center section has only one module instead of two. Maybe the 764 going Polaris would mean it should be moving off HI routes.