Hi w124,
From my experience back in 11/10/09, when I had my Interview @ LA DO, it went very smooth and simple
mine was based on 5 Yr GC, my interview did not last over 10 mins going through the application to confirm the entries/answers
and then the 10 questions & read/write and then I was out of the office with a Congratulation you are recommended for Citizenship.
Even one of the questions I answered it right but the IO said it is wrong, it was Q#4 I think, I did not even argue with him, he asked me another one.
So, the key is :
1) Relax
2) Relax
3) Relax
4) Be prepared in regards to the 100 questions, what I did, Ihad the CD in my car listening to it whenever I'm driving, I did not look in the book even.
5) Be prepared with documentation based on your case, taxes, bank stmts, birth Cert, Marraige Cert., All Passports, etc.
6) If your wife's application is 3 YR marraige based, it is better if you go with her, and if you have kids also to show live proof that you are guys still married
7) Go early than your App. to have time to relax, for me I do not like to review questions while waiting
And the most important thing, the IOs are all kind, smilly faces, sence of humer, so there is nothing to worry about.
And finally Good luck for your wife