I've never taken a MS exam that took longer thant 75 minutes for me to complete. I had 2 minutes left on this one and got a 646.
This was no 70-291 v2 exam, this was it's own exam with questions sprinkled with material you are expected to know from the 291 in order to answer the question. Ouch!
My mistake: Clustering. I didn't think I would get hit that hard with it but I ended up with 10 NLB/Clustering questions.

Needless to say, I have a feeling a got a few wrong as I only studied that chapter once. Ouch!
All of my categories except 'Plan, Implement & Maintain Server Availability' were at about the 60% mark or higher, with this category ending up around the 30% mark. Ouch!
Finally, the one thing that might have tipped me over was on a CA sim I needed to request a particular type of certificate through the web-based console and couldn't remember for the life of me, the default URL. I entered "
http://<server_name>/certreq". Needless to say that wasn't it and I have a feeling I lost a lot of points because of that one.
Anyway, enough about that. I feel good about the majority of the materials but at 50 questions w/5 sim's & 3 Drag/Drop questions, I am not looking forward to taking it again. I will be however, with a target date of May-15th, God willing.

Good luck to the rest of 'Rat Pack' that is on course to take this exam!!!
p.s. This was my First FAIL and boy did it sting to see that screen!