I flew hnl -pdx and then sea-hnl last week.

On the flight to pdx i opted out of my "upgraded" seat and stayed in 17

On way back to HNL i was able to "upgrade" to 6D. I dont think I would pay for a premium seat but as a free perk its ok. It was annoying that the curtain is basically at the end of the arm rest in row 6. It was almost as if they didnt move it while they changed the layout.