Over the last two seasons, Shields is 9th in both leagues in pitching fWAR between Hamels and Greinke.
http://www.fangraphs.com/leaders.asp...ter=&players=0
I suspect the fact that Shields is not a "name" guy or that hyped up is causing some of the negative reaction. He's really very good. Two years of him was never going to come cheap.