T3 is physically the smallest terminal at MAN, but it sees periods of intense passenger demand coinciding with waves of departures by Ryanair and FlyBe in particular. Air France / KLM, British Airways and American Airlines also contribute to busy periods there.
I have passed through T3 several times this year, predominantly at busy times of day, using services operated by Ryanair, FlyBe, Sun-Air and Air France. And on each occasion I have found that the security process, although faced with very high levels of throughput, was well-organised, friendly and kept moving well. Ten minutes was about the average transit time. This is a vast improvement from a couple of years ago. More noticeably, the inbound queues at UK Border cause considerably fewer delays than they used to. Proactive queue management has been introduced and there has been real effort to maximise use of e-gates for passengers with appropriately chipped passports. This is a huge improvement over previous experiences.
My slowest transit of MAN security this year was a departure through the Jet2 area of T1. This took about 25 minutes, but about half of that was the result of being picked out for a baggage check. Again, this was around 07:00 on a Summer morning, so an extremely busy time. I'll be departing from T2 in the near term, so I will have the opportunity to see how a recent transit of the security process there compares.
I have to say that for speed of security processing, MAN has been up there with the best of my experiences this year. A number of airports overseas have been considerably slower. Most notably an Eastern European airport with a single Dash 8-400 departure all morning through to 12:00. They insisted on thoroughly searching every passenger and all baggage for a domestic flight, not just the few people who triggered the alarm on the x-ray arch. Maybe they felt a need to justify their existence. So volume of passenger throughput is not the only factor in speed of security processing. MAN compares very well in my experience.