I agree that Mann was uncooperative with McIntyre and McKitrick, and because of that, he will have an uphill battle in the minds of the general public convincing them that his analyses are correct, after the editorial commentaries on the McIntyre and McKitrick paper.
However, given that there are independent analyses of climate proxy data that show the same general patterns as the Mann et al. papers, and which do not show the big peaks that McIntyre and McKitrick derived from the erroneous data set that they analyzed, it's unfortunate that the McIntyre and McKitrick paper as written is in error. They didn't compare their results to other researchers results; they were focused on Mann. They've thus succeeded in doing two things: they've shown that Mann is an arrogant academic that does not wish to descend from his Olympian perch; and two, they've shown the danger of publishing without first checking to see if you've done everything correctly.
But they've won the public-relations battle, so perhaps they've done what they set out to do (put Mann's work in a bad light), whether or not they were ultimately correct or not.
I read that pdf file and what I see is a growing trend, not only in this case but others, to find statistical excuses for adjusting the data set upwards.
The argument with Mann's data analyses is not with the instrumental data record that covers the late 1800s to present. So he's not "adjusting the data upward". The argument is that his data analyses reduced the apparent scope and intensity of the Medieval Warm Period warmth and the Little Ice Age cold. When you look at his results and the results of other groups, it's apparent that both periods are present, but their variability is minimized because global data sets have been created. For example, if you compare Mann's data to Esper's Northern Hemisphere tree-ring data, Esper's data has more variability, which is an expected result.