Not taking sides here as I still can't make my mind up on Shed - his clangers can be the worst of game-changing howlers but his best can be just the opposite - but I thought I would chuck a summary of his stats up in response to Tucker's question re: how many 20+ possession games.
He played 16 games in 2007 averaging 10.3 disposals per game, no 20+ games, 9 games >10, 35 tackles @ 2.2.
He played 16 games in 2008 averaging 11.6 disposals per game, no 20+ games, 4 games >10, 30 tackles @ 1.9.
He played 15 games in 2009 averaging 12.6 disposals per game, no 20+ games, 3 games >10, 30 tackles @ 2.0.
He played 22 games in 2010 averaging 18.8 disposals per game, 8 20+ games, no games >10, 76 tackles @ 3.4.
He played 20 games in 2011 averaging 15.6 disposals per game, 5 20+ games, 1 game >10, 58 tackles @ 2.9.
He has played 16 games so far in 2012 averaging 17.4 disposals per game, 5 20+ games, 1 game >10, 41 tackles @ 2.6.
Interestingly, his stats show a marked increase since Hardwick and co took over so in fairness that should be considered when assessing his performance/worth. Also, I have a recollection that he played under an injury cloud for some of 2011 so there are possible reasons for the slight decline from his breakout 2010 season.
I know that stats don't paint the whole picture but they do show trends and highlight points that might otherwise get hidden in the emotion of player assessment.