Was just there this weekend. Customs line was so short on arrival that we didn't even use our FastTrack slips and saved them for another time. About 3 minutes in line. On the way back, from waiting at check-in to the lounge in about 15 minutes.
I do believe that it can get bad- just have not been experiencing that. it's been a piece of cake and very fast. Add to that that things are somewhat far apart and it gives great opportunities for a walk, and it can't be beat.
Yes, I am being serious. This has been our experience in about 6 or 7 trips the past couple of years, both connecting and O&D.
I'm sorry that others have not had the same experience
Cheers.
Same here. I flew into and out of LHR two weekends ago -- couldn't have gotten through immigration, customs, or security any faster. Longest wait was maybe five minutes for security.