Those "Knee Defenders" are ridiculous. All it would take would be the person in front calling a FA and asking why their seat couldn't recline and the defenders would be off.
Not to mention, what would happen if the individual in front reclined and pushed with such force as to break the table/tray behind it. Wouldn't the individual using the knee defenders be liable for that damage to airline property?
Knee Defenders seem too risky to use to me. Not to mention its rude.
Personally I've never had anyone raise their seat when it was time to eat. As for me, I recline it when I need to sleep and bring it back up when I'm awake out of courtesy.
A good way to get folks to bring their seat back up is to muster up a 'nasty' mucus filled cough and to cough on their hair. That usually brings the seats up pretty quick.
Although I must admit, its been about 3 years since I've flown, have the seats/recline changed that much? Honestly the differnece from 'up' and 'recline' was hardly noticeable to me.