I would say the a very important especially if you don't fly very often. The problem with the BA videos are they are way too long! I don't give a crap about the teddy etc.
Even though I have seen them 100s of times I kind of watch them still, at least I put my book or paper down especially in row 1 of CE with a FA right in front of you. It drives me MAD when other people carry on having their loud conversations during the video. Even if the don't want to watch it the could shut up for a couple of minutes and at least pretend.