I just had my interview earlier today. I got there 30 minutes early. Waited in the waiting room for about 35 minutes till my name was called.
The intervewing officer was a nice lady, not intimidating at all. Funny thing is that she was wearing a badge labeled as Visitor. Not sure why, maybe she's new or a temp?
Anyway, we went to her office. She asked for my driver license and permanent resident card. She then asked me to raise my right hand and swear that I would tell the truth. Then she went over my file. She did a quick review of all my paperwork including the ones that I submitted for my green card back in 2000. She then went over my N-400.
She asked if I'm still at the same address and phone number, same job, still unmarried, etc. I noticed that she didn't ask if I have been out of the countries between the time I submitted my N-400 and today, she just checked that section of N-400. I immediately told her that I've been out of the countries twice for about 15 and 11 days. She updated my N-400 but didn't even ask to see my passport to prove what I just told her.
She then went over the rest of my N-400 whether I've been in communist party, registered to vote, if I'm willing to bear arms, take oath, etc. She asked me if "I have been in trouble with the police". I had two speeding tickets back in 2005 (less than $150) but I don't consider that as being in trouble with the police so I answered her no. If she had asked me if I have been arrested or citated then I would have told her about the ticket. But since she didn't ask me that way, I just kept quite about my ticket

She also didn't ask to see my selective service card. I had it with me so it wouldn't be a problem if she did ask me.
She asked me to print my name on the 2 places on the last page of my N-400 eventhough it said "Applicant Signature", she crossed out the word "Signature". I asked her if she asked me to write my name in block letters and she said yes. I told her that I've head some people were asked to write their name in cursive, some were asked to sign like signing a check. She said that there is no consistency between each DO. She said that she used to ask people to sign like signing a check in other DO but when she first got to Seattle DO, she was told to ask for print name instead. Weird

Anyway, she also asked me to sign my photo, this time like signing a check.
Next, she asked me to read and write a very simple sentence. Then she asked me the citizenship test question. I told her I want the old one. She said she's glad that I chose the old one cause the new ones takes longer time to go through

She asked 6 questions and I got all of them right. They all really easy questions but I got the 13 states question as the last question. I've had a feeling that with my luck, I would probably get that question so I've made sure that I know all 13 states by heart

Next she asked to see my passport, I gave her my passport but she only wants to see my old passport. Good thing I brought it. I gave it to her and she brought my old passport to her supervisor. She came back 5 minutes later and told me that she had to check my old passport and asked her supervisor to sign her approval recommendation letter because in 2004 I had my luggages inspected at airport custom. She said that per policy, she had to ask her supervisor's review and signature in this situation eventhough my luggage inspection did not find anything illegal. Weird policy, but what the hell, no harms done in my case
So then she asked me if I can come back on Friday October 10th. I said yes, she then gave my oath letter dated October 10th. I was like "whoa". I never expected to get the oath ceremony 4 days after my interview, I though that I would have to wait until end of October at the earliest. She said that they normally don't have ceremony on Friday but they're trying to get as many people processed before the voting registration deadline. It looks like Seattle DO has finally done a better job
So that's my interview experience. All and all, it took about 30 minutes (plus another 35 minutes waiting). It was painless and not intimidating at all.