I went through T3 the other day and used the facial scanner at the entrance to fast track and then at the gates by 142.
Generally carry my passport and a driving licence anyway, so not too fussed should I get asked for anything.

Security wise, 5-10 minute wait whilst the slowest person ever (obviously shocked at the fact liquids etc. aren't allowed, this being a brand new thing) removed everything at a snail's pace from his collection of bags. Normal queue, which was small, mostly dealt with first.
Didn't get pulled aside for secondary and passed the scanning without something that wasn't there being detected.