I was on one yesterday and realised how much I hate being squashed up next to strangers (especially if in the middle seat, luckily I had a window seat yesterday)
You can basically only put one arm on an armrest.
A girl next to me was asleep and kept on rolling her head all over the place, moving her legs into my leg area etc.
Just think the limited room is awful.
She got up 3 times for the toilet in a 3 hour flight too and it's just annoying for the person who has to keep standing up.