One thing I've begun to dislike is that traditional IFE had polarising or directional filters so you couldn't see the screens of seats around you. iPads being used on some flights now don't so you see a sea of screens and in some cases some movies could flash quite some bright light from long away.

But now a resent plane I was on (I forget with who) the inbuilt IFE also didn't have these directional filters which was really annoying as you could see basically every seat beaming into the dark cabin.

Qantas are doing streaming in an app for some domestic planes now (pretty much all the ones that hadn't got the upgrade to the seat-back screens - all their planes that fly international have screens though). It's actually really good - an iPad has a way better quality display than anything I've ever seen in a seatback and the content library is larger if anything. All they have to provide is a USB charging port and a thing sewn into the seat that you can hook most cases over.

IFEs seem pretty popular still on long haul. On short haul they were always a bit useless. I'm a big fan of the recent trend to have mains power points in the seats so you can use your laptop or what have you.