It is really quite annoying that they have brought these back in, albeit in a different terminal. They had them in T1 for a fair while, but removed them as it appeared that it took more staff to help people through them than they actually saved on staff costs (thankfully the fasttrack lane was always a manned one though).
MAN do seem to be happy to try new technology to speed up / reduce staff costs, but it doesn't always work.
Having moaned above, I do still much prefer the whole security experience at MAN to LHR. The staff are friendly (they talk to you rather than barking orders at you) and fasttrack is much faster than the normal lanes.
T