We had our appointment at the US Embassy for our daughter's passport, birth registration, and SSN this morning. The appointment was at 9:15am. We drove from Leeds and got stuck in traffic 3 miles from the embassy that took nearly 45 minutes to get through. We went to Gould Pharmacy to get her pictures and were (thankfully) in and out in less than 5 minutes, despite there being a lot of people there for photos. We managed to get to the embassy right at 9:15. There was no one at all in the citizens' line and only 3 people in the non-citizens' line. We waited in the citizens' line for about 3 minutes before going into the little security building and leaving our cell phone and going through screening.
After that, it was about a 5-minute wait to submit our documents and applications inside, and then another 45 minutes total before we were able to get the heck out of there. Although they kind of grilled me about where I grew up in the US, where I went to school, etc. which was weird. They said 2 weeks for her passport/registration and about 2 months for SSN. So we were out of there well before 11 (we stopped by the IRS office for a few questions and waited a while, but it was a million degrees in there with a long wait because they only have one guy there to help people so we left).
So really, not too bad at all. Our ride wound up parking right beside the embassy at a metered spot, which cost £9 (ouch!). The courier service via the embassy was £14.50 (the post office said they "don't do prepaid special delivery" per what the embassy web site suggests, so we were kind of stuck with it).