I agree - from what I've heard the psychometric testing is a very important part of the interview. I got washed out on the first day - so I can't personally comment so much on the rest of the testing. But I am sure the compass testing does count for a decent part of the interview too as I feel it's why I didn't get through - unless there was something that I did very wrong in the sim which I'm oblivious of.
That being said, the guys who did their sim in ATL they were told that they'll be coming back the next day in the morning even before the compass testing was done. So with that said those guys may have got a free pass - as they effectively made it through day 2-3 without the EK folks even knowing the outcome of their compass testing.