Having just experienced T5 for the first time myself I have to agree with most of the nay sayers on here! It really is embarassing.
Early morning flight from YYZ with Mrs MAC and less than one year old MAC junior. Connecting flight to ABZ. Did not realise that we would go through FULL security again joining up with all the other flights that have arrived at 6am AND all the people who have just checked in. Chaos! To make matters worse Fastrack was at the other end of the security area which meant that people were having to push past 1000 other passengers....which lead to MAC junior being clobbered quite heavily whilst in his stroller. This lead to me and the wife yelling at the businessman responsible which lead to security singling me out which lead to another passenger leaping to my defence which lead to him being pulled out the line (he called security a waste of space...which I didn't think was a good idea at 7am!).
After a pointless argument we got to the x-ray machine where my son's medicines (all in the correct bottles and bags) and jars of baby food were all made to be opened there and then for me to taste in front of security (even though they had been fine with it in YYZ...as there were in the correct volumes). I pointed out to security that once the jars had been opened they had to be used within 2 hours and my connecting flight was not within that time frame. I was told of the security risk (and me pointing out that I am an air traffic controller with ID went down like a lead balloon)....and told I would have all the food and medicine confiscated if I did not taste them!.
Once we got through security we found the supervisor who was dressing down the guy who had defended us in line. When I told him that my son had been hit really hard in the arm due to the logistics of the security area he went really sheepish...and blamed BA. Apparently they want fastrack at the other end due to it being closer to their lounge.
Oh the joys! You get slagged on PRUNE for criticisizing the UK and Heathrow in particular..but come on...from my perspective it is embarrassment for a country that could and should do so much better! I have no problems in YYZ with security whatsover!