Where you are met, and what it costs
Stansted's Express Set Down area sits outside departures and works for both drop offs and short collections. It runs around the clock, and the charge steps up sharply: one rate for a stay of up to 15 minutes, and a much higher one beyond that, up to a 30 minute maximum. Both are covered by your fare.
That step matters on arrivals. A drop off is predictable, so the set down area suits it well. A collection is not, because border control and baggage reclaim can run long, which is why a pre-booked driver may use a longer stay arrangement instead and meet you at a confirmed point. With meet and greet your chauffeur comes through to arrivals with a named sign and walks you to the vehicle.
There is a free drop off option in the Mid Stay car park, further from the terminal. It is the cheaper way to do it under your own steam, and irrelevant when the charge is already inside a booked fare.
Journeys to and from Stansted
Stansted serves a different catchment to the other London airports, reaching north and east rather than into the city. Cambridge to Stansted transfers cover the shortest and busiest of those routes, and Colchester to Stansted transfers serve north Essex. From further afield, Manchester to Stansted transfers handle the long run south.
Airport to airport journeys are regular here, since Stansted's network does not overlap much with the others. Luton is the closest comparison for schedule and route, so if your flight actually leaves from there, compare Luton airport transfers instead and allow a real buffer for reclaim and check in at the second airport.
Choosing your vehicle
Business covers most journeys out of Essex, Standard adds a fourth seat, and Business XL, the people carrier class, takes the luggage when a family of five travels together. First and Executive are there for the occasions that warrant them.
Above five passengers it is two vehicles rather than one larger one.
Group transfers from Stansted run as multiple vehicles rather than a minibus.