Well, yes, London is just two-and-a-half hours from Tallinn. But getting there from Tapa seems just as arduous as leaving from Chicago.
First, there is the trip from Tapa to Tallinn. Okay; it's about the same as taking the el from the Loop to O'Hare. But the check-in time of your flight has to jive with the train schedule. If it does, then the stop at Ülemiste is not far from the airport. No, passage is not as smooth as it is from the O'Hare el station, but it is still within walking distance. Never mind that it could be pouring down rain or that there might be a foot of snow on the ground. Once you jump across the gap between the train and the platform and then get down the 30-40 steps at Ülemiste, the rest of the way to the airport is pretty much flat. If your plane leaves in the middle of the afternoon and in the early evening, though, you need a Plan B to get to the airport.
Secondly, in European airports there's these paternalistic "gate" open and "gate" close times. So "What time does your plane leave?" is inconsequential, because you have got to be checked in before the "gate," that is, your airlines' check-in counter, closes. For example, our easyJet flight left at 11.55, but the check-in counter for the flight reportedly closed at 11.15. So I added the customary "be at the airport two hours early" to that time, and we were there before the damn counter even opened!
Once you have gone through security, checked your email on one of the four computer terminals at the real gates, and squirted some cologne from the duty-free shop on your neck, the easyJet flight to London is relatively nice. Due to construction to expand the airport, we took a bus to the plane and got to board from both the front and rear doors! The Airbus A319 planes that easyJet flies are really very nice and, despite the two rows of three seats on either side of the aisle, very spacious.
The only good thing about our 6.55 flight back to Tallinn (the "gate" closed at 6.15, the National Express bus left at 4.40, we were up at 3.30) was that, once we got to Stansted, we saw that there were a wholeheckavalot of people who had earlier flights to catch than we did.