I think that my findings have been in the Fast Track or the First Wing. I had long wondered at Fast Track whether the people deliberately made complications. They seemed to be the slowest that I had met. As for connections I found the staff disinterested and surly. People who had tight connections (for no fault of their own) seemed to be singles out for slow attention.
As I say, these are my opinions only and are purely subjective. I wasn't really trying to compare this airport with that as T5 and BA are so interwoven. I really do think that it's high time that BA did something about this as it does not enhance their image one bit.