In regards to experiences -
I am a 11B2V out of Fort Richardson Alaska, been in since January 2005. In Alaska attended and passed NCO of the quarter battalion, brigade and post, 3rd Place NCO of the year USARAK, and E-5 promotion board.
Deployed to Iraq, SAMC boards offered towards the end of our deployment. I've been a Sgt since August 2006 (so just over a year). 4th BDE 1st ID offered a board and most of the people that went through were in there for about 30 minutes.
I attended 4/25 BDE Board and was selected to attend 3rd ID Division board (our unit falls under 3rd ID over here).
Board lasted 1h22m on average for each of us. As was mentioned before by someone, the board asked a lot of board questions in situational settings as compared to purely situational questions.
Further, they performed an inspection on your weapon system and asked characteristics of it. An indepth look at your leaders book and citing questions from it in regards to your soldiers and their welfare and promotability / leadership status.
The toughest part I had was the NCOER process as I do not have much experience in them and a strong working knowledge in much of the other topics. Also being unmarried and without kids, I had to talk to my married soldiers and find out what programs and groups their spouses and children had available.
All in all, the board was not as hard as I thought it would be, though it was still difficult.
Your reciting of Audie Murphy's bio, nco creed, army song, soldier's creed, 3rd ID song all take place at the position of attention which was a bit nerve racking for the BDE board but smoother at the Division board for whatever reason.
Anyways, I highly recommend that younger soldiers take the time and effort to accomplish this board. It seems a daunting task, but you will learn so much information in the process that even if you do not pass the first time, you are separating yourself from your peers by showing your dedication and potential, and you'll have a much broader understanding of the military & more specifically NCO process as a result
End state: Inducted. And very happy. Now if I just survive these last few months in Iraq I'll be even happier

Sgt Soler