I had a final assessment day with PA a few weeks ago having in the prevoius few weeks done 4 other very enjoyable and succesful assesments. I couldn't beleive how horrid it was! In the first round interview the woman didn't amke eye contact, asked me pretty much the same list of questions I had got off Google as practice ones, ummmed at inappropriate moments and just wrote everything I said down on a note pad.
At the assessment day they were thoroughly disorgnaised - my interviewer turned up 1 1/2 late after i'd got up at 5.30 that morning to get there! They also came across as quite agressive - I understand that consultancy need to challenge us (and want this) but it actually felt like they were seeing how mean they could be until we cracked!
Also the case study was nothing but a number crunching exercise with 6 people watching and firing questions as 6 grads! We had already had (and passed numeracy tests so I really didn't feel the need for this!)
I had amazing experinces at Capgemini, BT Consulting, Atos Consulting and Capita - all of whom made me feel really comfortable, were knowledgable - wanted to interact and help me to perform as well as I could!
I would be really interested to know if others have had any good or bad experiences on assessments days at the big companies - it shouldn't all be about them judging us!