I got to the embassy at 9:45 for my 10:30 interview expecting to be turned away for being too early, but was just pointed to join a line. Next to me was the 10am line at around about 10:30 the 10am line started to move so there were clearly some delays. It did annoy me that at around 11am people were still joining the 10am line, if you can't be bothered to turn up to such an important interview on time then you should be forced to wait or reschedule as far as I'm concerned. Anyways, once I got in at about 12:00 I waited for 20 minutes, got called to a window to hand my documents in, got asked my name, asked who my co-sponsor was in relation to my wife (her brother) got asked why her brother had a different surname to her ( I pointed out that it was because my wife took my name when we got married) then I took my xray and sat back down. About another 20 minutes later I got called up to a second window to sign my form and swear that I was telling the truth.
After that all I had to do was hand over a form for delivery of my passport and visa back to me and pay for it.