I have a smaller than average head. The 2 vertical side folds are too wide to prevent my head from sagging off to left/right, not to mention forward of course.

I have a smaller than average head. The 2 vertical side folds are too wide to prevent my head from sagging off to left/right, not to mention forward of course. Lack of static head position is the biggest hindrance to sleeping seated. Back-Inclination, Leg-Space, Arm-Rest are all secondary. If you're tired enough, a head-harness is enough to catch a solid 4-hr nap.