Not a pleasant experience. The main problem with STN is that it is running way over its capacity with the airport running out of places to sit down even on a (presumably relatively quiet) mid Friday afternoon in January. What it must be like at peak times I dread to think. However it did take only about 15 minutes to get through security outbound. Note that once in the main terminal you can't go to use the lounges (which are in satellite 1) unless your flight is departing from those gates as there is no way to return to the main departure hall (so e.g. Priority Pass is useless). On return at 10.30 Sun night having sprinted past other passengers on our flight and on others we were held for about 3 minutes in the previously mentioned corridor before we could join the queues to get through customs. It took us about 25 minutes to get to the front of these queues despite all available desks being open. Presumably those behind us were still stuck in the corridor. Then went straight down to the Stansted Express. This did run on time but the train was filthy seats were missing etc. I felt quite ashamed that this is some visitors' first view of Britain.