Appeared @ Embassy 30 min in advance of 10:30 appt. Was able to accompany my fiancee throughout the entire process.
Got our appt. # at the outdoor kiosk and was told proceed to security check. Passed thru security, and across a courtyard to the entrance. There was a very long queue. DO NOT wait in that queue. Go thru door on the left and immediately to the front desk. Tell them you're there for a K-1 visa. They'll tell you to take the lift to the 1st floor. Once there go left then turn left again and watch the screen for your # to be called. We waited 15 min. before our # was called. Answered brief questions - showed a couple documents (DS-160 etc) and were told to again sit down and wait. In less than 20 min our # was again called. Went to another nearby window where Ewa was asked for fingerprints and to affirm her answers would be truthful. She was asked where we met, if she'd ever changed her name (no) , ever been to the US (no) , been married before (no), I was asked my profession, if I'd ever been married before (yes) and I mentioned I'd come to the UK just 2 days earlier to be of help at the interview. We were then told the visa would be approved.!!
The entire process from beginning to end, took 1 hr 20 min.