Had my N400 interview in Cranbury yesterday, and it's one of the best govt offices I've visited. Literally everyone in there is pleasant. Everything took place on one floor. I arrived about 30 minutes before my appointment and was told to come back 15 minutes later. So one advice is not to go too early, they'll ask you to come back.
Entered the building, the security checked me in then I went to window 1 for her to scan by letter, then assign a number. After that I sat for about 10 minutes and my number was called before my appointment time. Interview was quick, after scanning my index fingers the officer dived right into the civics question no warning. Lol. Then the yes, no questions. They ask you to write on an iPad with your finger instead of a sheet of paper (yayyy for being tech forward)!
The interview lasted less than 10 minutes and I was given a sheet of paper with results and told to wait outside for the oath. The office is new so no one knew exactly what time the oath was. We were told some days they've done it at 10:30am depending on appointments for the day and when they have critical mass. Eventually it happened at 12, lasted 10 minutes. By 12:15 I was a US citizen and out of there!
The office is very nice - much smaller than Newark. Surplus parking and it's free! The supervisor who administered the oath told us this is the first of many offices in the US to come with this model. We were the 10th group to have been sworn in at the location. No name change available at the location, so if you requested a name change and your interview is here, you won't be sworn in for months or longer. That process hasnt been established there yet.
Cranbury USCIS office is great! Had my interview and became a U.S. citizen all in under 3 hours!