Just a slightly different take on the situation for a change....
Last Monday (11th) I flew as pax out of UK for first time since advent of new security. I decided to leave lots of time in view of both the measures, the date and the evening rush. So, I am doing LHR-PRG out of T2, and decide to time the process to see just how bad things are. I started the stopwatch as I paid off the taxi outside the terminal, kept it going all through check-in (not pre-checked, and with luggage for the hold) and security, finally stopping when I retrieved my bag, PC and shoes at the end of security.
Total time? 7 minutes and 30 seconds. Start to finish. I have never done T2 that quickly before.
Oh, and the security staff with whom I had contact were all pleasant, efficient and tolerant (anyone really know how to explain "just one bag" in Japanese?) in spite of being at the end of a long day.
So, it can be done!