Visa Stamping from Canada/ Mexico

Our background:- This is our first H1B visa stamping outside India. We are in US for past 10 years and waiting for our green cards since Dec 2010 in EB2 India category.
I am on H4 EAD and my spouse on H1B visa . We work in Engineering (non IT) & Medical fields respectively.
Visa interview experience:-
Our interview slot was 10.15 hrs and we reached the Embassy around 0950 hrs . Since we booked a room at Byward Blue Inn on the Clarence St. it was just a few minutes walking only to the embassy.
In less than 10 minutes time we were let inside after the normal security frisking etc. There is a small storage place inside the embassy for a smartphone and car keys etc. There were around 50 people already there before us . Most of them were Indian passport holders ( not necessarily for H1B visa) . After waiting in the line for around 30 minutes we were called for finger printing (all ten) and verifying of mandatory documents and photographs. Everything went well and within 15 minutes we were in line for the crucial VO interview .
After another 35 minutes waiting we were called by the male VO for the interview.(there was another female VO also )
Questions:-
To my spouse (on H1B)
Q:- 1. So you are working for --------------- what exactly is your work there?
Ans: I work as a ----------------------------
Q;- 2. What is your green card status ?
Ans:- We are waiting for our green cards since 2010
The VO seems to be taken aback by the answer and didn’t respond to it .
Now to me ( on H4EAD)
Q:-1 So you are working for --------------------- on EAD and what is your work there ?
Ans:- I am working as a ---------------- there.
Q:-2 Can I please see your EAD card?
I showed him my EAD card and seems to be satisfied with it .
Q:-3 You told you are working as a --------------------- but what exactly you are doing there ?
Ans:- I am working on some of the most sensitive ---------- systems in the world as a --------------- Engineer.

Your visas are approved and the passports will be returned in 3 to 5 business days.
Apart from the passports and I-797 original notice of approval he didn’t ask for any other documents.
Around 11.30 Am we were outside the embassy .

Since we have a close relative in Ottawa after the interview we moved to their apartment and waited there for our passports . We received them on 9th (Wed) and flew back to US on 13th Via Montreal after sight seeing for a few days in Ottawa and Montreal.
At the Montreal airport US immigration was also not much problem . Just asked us where we are from and what we are doing there.