Hi all,
Just wanted to describe my experience, it might help someone.
I had my interview on Jan 21st. I was put into administrative processing because I overstayed my tourist visa in the past. They returned my passport to me and said they'd let me know when tht AP is completed, but I shouldn't worry, it's a normal thing.
On March 4th I received an email from the embassy to submit my passport, which I did throught the DX courier service.
On March 19th I received an email to schedule my fingerprint scanning. I scheduled it for 2 days after. The process during the fingerprint scanning was the same as during the interview - you go to the window to check in, go through security, go throught he reception and get a number. Then I waited for the (same) immigration officer who asked me some additional questions and scanned my fingerprints. Then he told me he "intends to approve my visa" and sent me home.
I was checking every day and the status of my visa wasn't changing, then suddenly it changed to "issued". On March 24th I received an email that my passport has been released, and it included a "tracking number". I tried to use this tracking number with DX, with MBE and with the Royal Post but it didn't work. It had a really weird format. I waited for 3 days before it started to be worrysome. I even tried to contact DX and MBE and nobody was able to help. So I googled it and it seems that there's no additional email which would tell you that your document is ready to be picked up. I just headed to the Charing Cross (Holborn) MBE location and the passport had been just sitting there for days.
So the whole process, from interview (with AP) to picking up my passport with my green card in it took about 2.5 months.
One thing to add. I didn't get any envelope along with my passport. It says that if you submitted all your documents electronically (which we did) you only get your passport and the immigration officer will see it in their computer when you arrive. Also, the (initial/temporary) visa in the passport is only valid for 3 months, in which you have to immigrate! Luckily I was always planning to relocate as soon as I get it.
The whole process is full of waiting, questioon marks, incomplete information and guesswork. I'm really thankful for VisaJourney and all the people in this thread to help me with my journey. It would be great if the US goverment was more transparent and upfront with the process, what's expected and when.