What was the hardest C3, C4 , and M2 exam for Edexcel?

I'm in year 12, and I'll be sitting C3, C4 and M2 in a few months, and I was just wondering which was the hardest paper for C3, C4 and M2 respectively between 2009-2015 inclusive (the three papers don't have to have been in the same year by the way, I'm technically asking about all three individually). I want to save this paper for last. As a plus, has anybody got any critical ranking (most difficult to least difficult) for these three modules.

Thanks in advance

I'm in year 12, and I'll be sitting C3, C4 and M2 in a few months, and I was just wondering which was the hardest paper for C3, C4 and M2 respectively between 2009-2015 inclusive (the three papers don't have to have been in the same year by the way, I'm technically asking about all three individually). I want to save this paper for last. As a plus, has anybody got any critical ranking (most difficult to least difficult) for these three modules.

Thanks in advance

C3 and C4 in year 12? Wow..

For c3 I would probably say it was june 2013. C4 were more or less the same and I can't comment on M2 as I don't take it

I think I remember the examiners' report saying that it was an exceptionally hard paper.

Dear God it was, I even remember trying the paper again (after having gone through it the first time) a few months after having done it, but no, it was still as hard...