the visa interview was very easy...for me, the whole interview only lasted for few minutes ...lol...the questions asked were:
"what are you studying"
"which university are you attending?"
"how do you know about this program?"
"are you going with friend?"

"your visa is approved."

That's all....lol...

but i would say its all depend on your luck ...depend on which interviewer you got...some interviewers are rather strict...