I'm assuming most (non-photo-printing) people have their screens set brighter than 120 cd/m² / nits, not that they have better screens.
As a not scientific example here are 3 random monitors sub $200 that are typical of what has been in offices I've worked in. For people not doing graphic / color work.
Acer SB220Q bi: Brightness - 250 nit ($130)
Dell 22 Monitor - E2222H: Brightness 250 cd/m² ($144)
HP Pavilion 22cwa : 250 nits of brightness ($134)
It sounds like you're editing on the ipad at a high brightness setting? So I'll ask you the reverse question: if you think your clients / viewers are looking at them on a duller screen, have you considered editing with your brightness turned down a bit more?