I posted on last week, here is the link to it
Detroit_Waiter "Detroit Applicants, For passport stamping" 10/3/01 1:24pm
I suggest go around 10.30 AM. Because a friend of mine said he had someone go in around 11 and was done in about 45 minutes and same with someone going around 2 PM, if You go later than that probably more people to delay your stuff.
Its just the waiting though, everything else is smooth and nice.