My cynical side wonders if the monumental cock-up at opening was deliberate, so that when they finally got it working as it should, it would attract loads of publicity from people saying how wonderful it is.
On the other hand I don't think BA could do anything deliberately and get it right!
I have yet to have the pleasure of flying via T5 as the World's Favourite Airline is far from being mine, and I hope it's a long time before I have to use them again.